An ore-blending optimization model for the sintering process is an intelligent system that includes iron ore characteristics, expert knowledge and material balance. In the present work, 14 indices are proposed to repr...An ore-blending optimization model for the sintering process is an intelligent system that includes iron ore characteristics, expert knowledge and material balance. In the present work, 14 indices are proposed to represent chemical composition, granulating properties and high temperature properties of iron ores. After the relationships between iron ore characteristics and sintering performance are established, the ＂two-step＂ method and the simplex method are introduced to build the model by distinguishing the calculation of optimized blending proportion of iron ores from that of other sintering materials in order to improve calculation efficiency. The ore-blending optimization model, programmed by Access and Visual Basic, is applied to practical production in steel mills and the results prove that the present model can take advantage of the available iron ore resource with stable sinter yield and quality performance but at a lower cost.展开更多
Structure model of granules, boundary value of nucleus and powder, and the relationship between granula- tion efficiency and boundary value were investigated. Granules of sintering mixtures are composed of adhesive po...Structure model of granules, boundary value of nucleus and powder, and the relationship between granula- tion efficiency and boundary value were investigated. Granules of sintering mixtures are composed of adhesive powder and nucleus. In the mixtures, particles larger than 1.00 mm act as nucleus and particles smaller than 0.25 mm act as adhesive powder. Particles with size between 0.25--1.00 mm can be adhesive powder as well as nucleus depending on the granulation conditions. When the boundary value is close to 0.25 mm, the granulation efficiency is lower than 50%. When the boundary value is close to 1.00 mm, the granulation efficiency is above 90%. The boundary value is influenced by the iron ore type, granulation moisture, fineness of raw materials and burnt-lime activity. Good adhe- sive capability, suitable moisture content, appropriate particle size distribution and high burnt-lime activity make the boundary value move towards 1.00 mm and improve the granulation efficiency.展开更多
Based on an analysis of the fractal structures and mass transport mechanism of typical shear-fluid-ore formation system, the fractal dispersion theory of the fluid system was used in the dynamic study of the ore forma...Based on an analysis of the fractal structures and mass transport mechanism of typical shear-fluid-ore formation system, the fractal dispersion theory of the fluid system was used in the dynamic study of the ore formation system. The model of point-source diffusive illuviation of the shear-fluid-ore formation system was constructed, and the numerical simulation of dynamics of the ore formation system was finished. The result shows that: (1) The metallogenic system have nested fractal structure. Different fractal dimension values in different systems show unbalance and inhomogeneity of ore-forming processes in the geohistory. It is an important parameter to symbolize the process of remobilization and accumulation of ore-forming materials. Also it can indicate the dynamics of the metallogenic system quantitatively to some extent. (2) In essence, the fractal dispersive ore-forming dynamics is a combination of multi-processes dominated by fluid dynamics and supplemented by molecule dispersion in fluids and fluid-rock interaction. It changes components and physico-chemical properties of primary rocks and fluids, favouring deposition and mineralization of ore-forming materials. (3) Gold ore-forming processes in different types of shear zones are quite different. (1) In a metallogenic system with inhomogeneous volumetric change and inhomogeneous shear, mineralization occurs in structural barriers in the centre of a shear zone and in geochemical barriers in the shear zone near its boundaries. But there is little possibility of mineralization out of the shear zone. (2) As to a metallogenic system with inhomogeneous volumetric change and simple shear, mineralization may occur only in structural barriers near the centre of the shear zone. (3) In a metallogenic system with homogeneous volumetric change and inhomogeneous shear, mineralization may occur in geochemical barriers both within and out of the shear zone.展开更多
A better understanding of solid-liquid separation would assist in improving the thickening performance and perhaps water recovery as well. The present work aimed to develop an empirical model to study the effects of o...A better understanding of solid-liquid separation would assist in improving the thickening performance and perhaps water recovery as well. The present work aimed to develop an empirical model to study the effects of ore properties on the thickening process based on pilot tests using a column. A hydro-cyclone was used to prepare the required samples for the experiments. The model significantly predicted the experimental underflow solid content using a regression equation at a given solid flux and bed level for different samples, indicating that ore properties are the effective parameters in the thickening process. This work confirned that the water recovery would be increased about 5% by separating the feed into two parts, overflow and underflow, and introducing two different thickeners into them separately. This is duo to the fact that thickeners are limited by permeability and compressibility in operating conditions.展开更多
Convective heat transfer associated with the circulation of porefluid in porous rocks and fractures within the upper crust of the Earth is substantial when the temperature gradient is sufficiently high. In order to un...Convective heat transfer associated with the circulation of porefluid in porous rocks and fractures within the upper crust of the Earth is substantial when the temperature gradient is sufficiently high. In order to understand the process of Snpolymetallic mineralization in the Dachang ore district of Guangxi, a finite element method has been used in this study to simulate both pore-fluid flow and heat transfer in this district. On the basis of related geological, tectonic and geophysical constraints, a computational model was established. It enables a computational simulation and sensitivity analysis to be carried out for investigating ore-forming pore-fluid flow and other key factors that may affect hydrothermal ore genesis in the district. The related simulation results have indicated that： （1） permeable fault zones in the Dacbang ore district can serve as preferential pathways for pore-fluid flow on a regional-scale; and （2） the pore-fluid flow can affect the salinity distribution. This latter factor is part of the reason why Sn-polymetallic mineralization has taken place in this district.展开更多
Cooling process of iron ore pellets in a circular cooler has great impacts on the pellet quality and systematic energy exploitation. However, multi-variables and non-visualization of this gray system is unfavorable to...Cooling process of iron ore pellets in a circular cooler has great impacts on the pellet quality and systematic energy exploitation. However, multi-variables and non-visualization of this gray system is unfavorable to efficient production. Thus, the cooling process of iron ore pellets was optimized using mathematical model and data mining techniques. A mathematical model was established and validated by steady-state production data, and the results show that the calculated values coincide very well with the measured values. Based on the proposed model, effects of important process parameters on gas-pellet temperature profiles within the circular cooler were analyzed to better understand the entire cooling process. Two data mining techniques—Association Rules Induction and Clustering were also applied on the steady-state production data to obtain expertise operating rules and optimized targets. Finally, an optimized control strategy for the circular cooler was proposed and an operation guidance system was developed. The system could realize the visualization of thermal process at steady state and provide operation guidance to optimize the circular cooler.展开更多
Sheytoor Iron Ore deposit is located in Yazd province of Iran (Bafq). The most abundant ore is magnetite, which can be seen in the form of mass and granular tissue in various forms of self-shaped, semi-self-shaped and...Sheytoor Iron Ore deposit is located in Yazd province of Iran (Bafq). The most abundant ore is magnetite, which can be seen in the form of mass and granular tissue in various forms of self-shaped, semi-self-shaped and amorphous. The main purpose of this study is to identify the geochemical relationship of phosphorus and sulfur elements and also three-dimensional modeling of mineralization of these elements in iron ore. In order to achieve the research goal, methods such as k-mean clustering technique, concentration-volume fractal as well as block modeling with kriging estimator and Inverse Distance Weighting (IDW) interpolator were used. The model of geochemical behavior of phosphorus and sulfur elements compared to iron is of great importance because these two elements are known as deleterious elements in mineral processing and steelmaking processes, which are the post-mining stages. Existence of geochemical model and identification of elements’ behavior towards each other play a key role in optimizing mining operations in order to achieve geometallurgical goals. The results of this study are the three-dimensional model of mineralization of iron, phosphorus and sulfur elements, separation of phosphorus and sulfur mineralization communities and also presenting the model of enrichment community of these two elements. All the results are in line with geometallurgical studies and can optimize the next steps by optimizing the mining process.展开更多
Grate-kiln-cooler has become a major process of producing iron ore pellets in China. Due to the diversity of the raw materials used and the multi-device multi-variable characteristics,this process still encounters wit...Grate-kiln-cooler has become a major process of producing iron ore pellets in China. Due to the diversity of the raw materials used and the multi-device multi-variable characteristics,this process still encounters with control problem. An attempt was proposed to deal with this issue. The three-device-integrated feature of the process was firstly analyzed to obtain control strategy,and then an intelligent control system using a combination of expert system approach and Takagi-Sugeno（ T-S） fuzzy model was developed. Expert system approach was used to diagnose and remedy the abnormal conditions,while T-S fuzzy model was used to stabilize the thermal state. In the construction of T-S fuzzy rules,antecedents were identified by fuzzy c-mean clustering algorithm incorporated with subtractive clustering algorithm,and consequent parameters were identified by recursive least square algorithm. The control system was applied in a Chinese pelletizing plant and the application results demonstrated its effectiveness of stabilizing the thermal states within three devices.展开更多
The Shizhuyuan W,Sn,Mo and Bi polymetallic ore deposit is one of the world famous superlarge ore deposits.The paper briefly introduced the geological setting and features of the ore deposit.Further,an ore－ forming mo...The Shizhuyuan W,Sn,Mo and Bi polymetallic ore deposit is one of the world famous superlarge ore deposits.The paper briefly introduced the geological setting and features of the ore deposit.Further,an ore－ forming model was put forward at the end of the paper.展开更多
A model GM （grey model） （1,1） for forecasting the rate of copper extraction during the bioleaching of primary sulphide ore was established on the basis of the mathematical theory and the modeling process of grey s...A model GM （grey model） （1,1） for forecasting the rate of copper extraction during the bioleaching of primary sulphide ore was established on the basis of the mathematical theory and the modeling process of grey system theory. It was used for forecasting the rate of copper extraction from the primary sulfide ore during a laboratory microbial column leaching experiment. The precision of the forecasted results were examined and modified via ＂posterior variance examination＂. The results show that the forecasted values coincide with the experimental values. GM （1,1） model has high forecast accuracy; and it is suitable for simulation control and prediction analysis of the original data series of the processes that have grey characteristics, such as mining, metallurgical and mineral processing, etc. The leaching rate of such copper sulphide ore is low. The grey forecasting result indicates that the rate of copper extraction is approximately 20% even after leaching for six months.展开更多
A model of iron ore sintering was built with consideration of fuel combustion, catalysis of sinter mixture as well as formation of melt and mineral, which was verified via sintering pot tests and showed a good fit to ...A model of iron ore sintering was built with consideration of fuel combustion, catalysis of sinter mixture as well as formation of melt and mineral, which was verified via sintering pot tests and showed a good fit to the experi- mental results. The effect of bed depth on temperature was reflected by the residence time in high-temperature zone, rather than the top value of the temperature, which was weakened by melt formation as well as hematite decomposi- tion. Moreover, the effect of bed depth, fuel content and distribution on sintering process was different, which was reflected by temperature profiles and the rule of calcium ferrite formation. The formation of melt as well as magnetite was a process which was decided by kinetic factors, while the formation of calcium ferrite was related to fuel blend- ing conditions, which is determined by thermodynamics when the fuel ratio inside sinter granules is low or fuel con- tent is high, otherwise, it is determined by kinetics.展开更多
In the early 1980's, the author proposed his view that copper-nickel sulphide deposts are of ore magma origin. For more than ten years, this view has aroused attention of his colleagues at home and abroad. In this...In the early 1980's, the author proposed his view that copper-nickel sulphide deposts are of ore magma origin. For more than ten years, this view has aroused attention of his colleagues at home and abroad. In this paper an attempt is made to deal with the genetic model for ore magma of copper-nickel sulphide deposits in more details on the basis of geological, geochemical, petrophysico - chemical and thermodynamic studies of the Chibaisong copper-nickel sulphide deposit in the Changbai Mountains, Jilin province.展开更多
The Tongling ore district is one of the most economically important ore areas in the Middle–Lower Yangtze River Metallogenic Belt, eastern China. It contains hundreds of polymetallic copper–gold deposits and occurre...The Tongling ore district is one of the most economically important ore areas in the Middle–Lower Yangtze River Metallogenic Belt, eastern China. It contains hundreds of polymetallic copper–gold deposits and occurrences. Those deposits are mainly clustered(from west to east) within the Tongguanshan, Shizishan, Xinqiao, Fenghuangshan, and Shatanjiao orefields. Until recently, the majority of these deposits were thought to be skarn-or porphyry–skarn-type deposits; however there have been recent discoveries of numerous vein-type Au, Ag, and Pb-Zn deposits that do not fall into either of these categories. This indicates that there is some uncertainty over this classification. Here, we present the results of several systematic geological studies of representative deposits in the Tongling ore district. From investigation of the ore-controlling structures, lithology of the host rock, mineral assemblages, and the characteristics of the mineralization and alteration within these deposits, three genetic types of deposits(skarn-, porphyry-, and vein-type deposits) have been identified. The spatial and temporal relationships between the orebodies and Yanshanian intrusions combined with the sources of the ore-forming fluids and metals, as well as the geodynamic setting of this ore district, indicate that all three deposit types are genetically related each other and constitute a magmatic–hydrothermal system. This study outlines a model that relates the polymetallic copper–gold porphyry-, skarn-, and vein-type deposits within the Tongling ore district. This model provides a theoretical basis to guide exploration for deep-seated and concealed porphyry-type Cu(–Mo, –Au) deposits as well as shallow vein-type Au, Ag, and Pb–Zn deposits in this area and elsewhere.展开更多
Based on conduction,convection and radiation heat transfer among the flue gas,kiln wall,and the pellet bed material,and on the basis of the coal combustion and analysis of reaction heat of pellet induration in the rot...Based on conduction,convection and radiation heat transfer among the flue gas,kiln wall,and the pellet bed material,and on the basis of the coal combustion and analysis of reaction heat of pellet induration in the rotary kiln,the temperature field model of rotary kiln was established.Using visual studio net,matlab and open source computer vision library as development tools,combining with the ActiveX data objects database technology,the temperature field simulation system for rotary kiln of iron ore oxidized pellet production was developed.Temperature distribution of pellet and flue gas in rotary kiln was dynamically displayed.展开更多
Simulation of the direct reduction conditions was performed in a laboratory furnace. Lump samples from natural hematite iron ore were reduced by a gas mixture of H2 and CO (H2/CO =1.5) at temperatures of 700°...Simulation of the direct reduction conditions was performed in a laboratory furnace. Lump samples from natural hematite iron ore were reduced by a gas mixture of H2 and CO (H2/CO =1.5) at temperatures of 700°C, 800°C and 900°C. The effect of reduction temperature on the reduction degree, reduction rate of samples and carbon deposition were investigated and discussed in this study. The thermo-gravimetric data obtained from the reduction experiments was run in a programme that calculates the solid conversion rate. Also, three models: 1) Grain Model (GM), 2) Volumetric Model (VM), and 3) the Random Pore Model (RPM), were used to estimate the reduction kinetics of natural iron ores. It was found that the RPM model result agreed best with the obtained experimental results. Furthermore, it gave better predictions of the natural iron oxide conversion and thereby the reduction kinetics.展开更多
This paper presents a model derived for quantitative evaluation and prediction of the concentration of phosphorus removed during pyro-hydro beneficiation of iron oxide ore. Potassium hydroxide was used as the leaching...This paper presents a model derived for quantitative evaluation and prediction of the concentration of phosphorus removed during pyro-hydro beneficiation of iron oxide ore. Potassium hydroxide was used as the leaching solution and the reaction vessel containing the solution and ore was heated at a temperature of 600℃ for 10 minutes. The results of the investigation indicates that the model;P = (e0.7827) S predicts the concentration of phosphorus removed, based on the concentration of sulphur simultaneously removed. It was observed that the validity of the model is rooted in the expression lnP = lnN + lnS where both sides of the expression are approximately equal to 4. The maximum deviation of the model-predicted concentration of removed phosphorus from the corresponding concentration obtained from the experiment was less than 3%. The concentrations of phosphorus removed per unit mass-input of iron oxide ore as obtained from experiment and derived model are 0.8917 and 1.0354 mg/kg g-1 respectively. Similarly, the concentrations of phosphorus removed per unit concentration of removed sulphur as obtained from experiment and derived model are 1.8838 and 2.1874 mg/kg (mg/kg)-1 respectively. This implies that the concentration of phosphorus removed is approximately equal to the concentration of simultaneously removed sulphur during the beneficiation process.展开更多
The optimization system, which was the subject of our study, is an autonomous chain for the automatic management of cyanide consumption. It is in the phase of industrial automation which made it possible to use the ma...The optimization system, which was the subject of our study, is an autonomous chain for the automatic management of cyanide consumption. It is in the phase of industrial automation which made it possible to use the machines in order to reduce the workload of the worker while keeping a high productivity and a quality in great demand. Furthermore, the use of cyanide in leaching tanks is a necessity in the gold recovery process. This consumption of cyanide must be optimal in these tanks in order to have a good recovery while controlling the concentration of cyanide. Cyanide is one of the most expensive products for mining companies. On a completely different note, we see huge variations during the addition of cyanide. Following a recommendation from the metallurgical and operations teams, the control team carried out an analysis of the problem while proposing a solution to reduce the variability around plus or minus 10% of the addition setpoint through automation. It should be noted that this automatic optimization by monitoring the concentration of cyanide, made use of industrial automation which is a technique which ensures the operation of the ore processing chain without human intervention. In other words, it made it possible to substitute a machine for man. So, this leads us to conduct a study on concentration levels in the real world. The results show that the analysis of the modeling of the cyanide consumption optimization system is an appropriate solution to eradicate failures in the mineral processing chain. The trend curves demonstrate this resolution perfectly.展开更多
According to grade-tonnage diagrams of nickel and zinc deposits, their critical grades are 0.4 % and 3. 4 %, respectively, and hence the former resources can be considered optimistic and the latter pessimistic. The gr...According to grade-tonnage diagrams of nickel and zinc deposits, their critical grades are 0.4 % and 3. 4 %, respectively, and hence the former resources can be considered optimistic and the latter pessimistic. The grade-tonnage diagram of gold deposits is convex downwards suggesting that the critical grade is 1 X 10-6 in the low-grade part. The ore value (OV)-tonnage diagram of all deposits In the world consists of three parts: high, middle and low vain f classes. The enrichment ratio (ER)-tonnage diagram of all deposits in the world ho consists of three parts: high, middle and low ratio classes.Nine quality categories defined by ER and OV are characterized by some keywords indicating deposit types as follows: category RH (high ER-high OV: 0. 7 %) by 'unconformity' and 'Mississippi Val-ley', category HM (high ER-middle: OV: 0.7 %) by 'vein', category ML (middle ER-low OV: 0 %) by 'sandstone', 'stockwork' and' dissemination', category LM by 'orthomagmatic',' laterite',komatiite and ' chemical', and category LL by 'porphyry', 'dissemination' and 'placer'. Category MM is not characterized by any keyword. If the commodities of a deposit are defined by both the enrichment ratio and the ore value, the defined commodities are relatively coincident for gold and nickel,but different for copper, silver and zinc, and greatly different for molybdenum and lead. Deposits containing lead and/or zinc are complimentary. If the commodity Ph+Zn is applied, most lead or zinc deposits are classified as Ph+Zu by both definitions. Accessory metals are commonly expected for deposits of kuroko-type zinc, epithermal silver, massive sulfide-type zinc and volcanogenic zinc, but uncommon for deposits of orthomagmatic chromium, chemically precipitated copper and sandstone-type uranium.展开更多
Based on the theoretical modelling of water-rock δD-δ18O isotopic exchange process,the evolution and sources of ore-forming fluid in four metallogenic epochs of the Jinduicheng su-perlarge-scale porphyry-type molybd...Based on the theoretical modelling of water-rock δD-δ18O isotopic exchange process,the evolution and sources of ore-forming fluid in four metallogenic epochs of the Jinduicheng su-perlarge-scale porphyry-type molybdenum deposit were investigated. It was revealed that in thepre-metallogenic and early-metallogenic epehs, the ore-forming fluid was a residual fluid derived from magmatic water-wall rock interaction at middle to high temperatures (T = 250 -500℃) and lower W/R ratios (0. 1 > = W/R >0.001 ), while in the metallogenic and Post-metallogenic epochs, the ore-forming nuid was a residual fluid derived from meteoric water-wallrock interaction at midd1e to lower temperatures (T = 150 - 310℃ ) and relatively high W/Rratios (0. 5 >W/R≥0.1 ). The meteoric water played an important role in molybdenum min-eralization, and at the main metallogenic epoch the W/R ratio reached its maximum value.展开更多
Five gold deposits (mineralization) were found in the study area by means of geologi</span><span style="font-family:Verdana;">cal mapping, soil geochemical survey and trough exploration engineeri...Five gold deposits (mineralization) were found in the study area by means of geologi</span><span style="font-family:Verdana;">cal mapping, soil geochemical survey and trough exploration engineering. The</span><span style="font-family:Verdana;"> ore-bearing lithology is mainly metam</span></span><span style="font-family:Verdana;">orphic feldspar sandstone of </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation, and the gold (mineralization) body is controlled by both structural factors </span><span style="font-family:Verdana;">and stratigraphic factors of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation. The genetic</span><span style="font-family:""><span style="font-family:Verdana;"> type is preliminary concluded to be volcanic hyd</span><span style="color:black;font-family:Verdana;">rothermal type, and the metallogenic age is late Variscan. In this paper, by studying the geological characteristics and metallogenic geological conditions of the gold orebody in the area, a regional prospecting model has been established, which is of great significance to better guide the prospecting work of similar gold deposits in the area and the region.展开更多
文摘An ore-blending optimization model for the sintering process is an intelligent system that includes iron ore characteristics, expert knowledge and material balance. In the present work, 14 indices are proposed to represent chemical composition, granulating properties and high temperature properties of iron ores. After the relationships between iron ore characteristics and sintering performance are established, the ＂two-step＂ method and the simplex method are introduced to build the model by distinguishing the calculation of optimized blending proportion of iron ores from that of other sintering materials in order to improve calculation efficiency. The ore-blending optimization model, programmed by Access and Visual Basic, is applied to practical production in steel mills and the results prove that the present model can take advantage of the available iron ore resource with stable sinter yield and quality performance but at a lower cost.
基金Item Sponsored by National Natural Science Foundation of China(51174253)
文摘Structure model of granules, boundary value of nucleus and powder, and the relationship between granula- tion efficiency and boundary value were investigated. Granules of sintering mixtures are composed of adhesive powder and nucleus. In the mixtures, particles larger than 1.00 mm act as nucleus and particles smaller than 0.25 mm act as adhesive powder. Particles with size between 0.25--1.00 mm can be adhesive powder as well as nucleus depending on the granulation conditions. When the boundary value is close to 0.25 mm, the granulation efficiency is lower than 50%. When the boundary value is close to 1.00 mm, the granulation efficiency is above 90%. The boundary value is influenced by the iron ore type, granulation moisture, fineness of raw materials and burnt-lime activity. Good adhe- sive capability, suitable moisture content, appropriate particle size distribution and high burnt-lime activity make the boundary value move towards 1.00 mm and improve the granulation efficiency.
基金The authors acknowledge the support of the National Key Basic Research Project No.G1999043206“Advanced School Key Teachers Supporting Program”of the Ministry of Education,the National Climbing Program of China No.95-pre-25 and 95-pre-39the“100 Trans-Century Science and Technology Talented Persons Cultivating Program”Foundation of the Ministry of Land and Mineral Resources No.9808.
文摘Based on an analysis of the fractal structures and mass transport mechanism of typical shear-fluid-ore formation system, the fractal dispersion theory of the fluid system was used in the dynamic study of the ore formation system. The model of point-source diffusive illuviation of the shear-fluid-ore formation system was constructed, and the numerical simulation of dynamics of the ore formation system was finished. The result shows that: (1) The metallogenic system have nested fractal structure. Different fractal dimension values in different systems show unbalance and inhomogeneity of ore-forming processes in the geohistory. It is an important parameter to symbolize the process of remobilization and accumulation of ore-forming materials. Also it can indicate the dynamics of the metallogenic system quantitatively to some extent. (2) In essence, the fractal dispersive ore-forming dynamics is a combination of multi-processes dominated by fluid dynamics and supplemented by molecule dispersion in fluids and fluid-rock interaction. It changes components and physico-chemical properties of primary rocks and fluids, favouring deposition and mineralization of ore-forming materials. (3) Gold ore-forming processes in different types of shear zones are quite different. (1) In a metallogenic system with inhomogeneous volumetric change and inhomogeneous shear, mineralization occurs in structural barriers in the centre of a shear zone and in geochemical barriers in the shear zone near its boundaries. But there is little possibility of mineralization out of the shear zone. (2) As to a metallogenic system with inhomogeneous volumetric change and simple shear, mineralization may occur only in structural barriers near the centre of the shear zone. (3) In a metallogenic system with homogeneous volumetric change and inhomogeneous shear, mineralization may occur in geochemical barriers both within and out of the shear zone.
文摘A better understanding of solid-liquid separation would assist in improving the thickening performance and perhaps water recovery as well. The present work aimed to develop an empirical model to study the effects of ore properties on the thickening process based on pilot tests using a column. A hydro-cyclone was used to prepare the required samples for the experiments. The model significantly predicted the experimental underflow solid content using a regression equation at a given solid flux and bed level for different samples, indicating that ore properties are the effective parameters in the thickening process. This work confirned that the water recovery would be increased about 5% by separating the feed into two parts, overflow and underflow, and introducing two different thickeners into them separately. This is duo to the fact that thickeners are limited by permeability and compressibility in operating conditions.
基金financially supported by the Natural Science Foundation of China(Grant No:10872219)
文摘Convective heat transfer associated with the circulation of porefluid in porous rocks and fractures within the upper crust of the Earth is substantial when the temperature gradient is sufficiently high. In order to understand the process of Snpolymetallic mineralization in the Dachang ore district of Guangxi, a finite element method has been used in this study to simulate both pore-fluid flow and heat transfer in this district. On the basis of related geological, tectonic and geophysical constraints, a computational model was established. It enables a computational simulation and sensitivity analysis to be carried out for investigating ore-forming pore-fluid flow and other key factors that may affect hydrothermal ore genesis in the district. The related simulation results have indicated that： （1） permeable fault zones in the Dacbang ore district can serve as preferential pathways for pore-fluid flow on a regional-scale; and （2） the pore-fluid flow can affect the salinity distribution. This latter factor is part of the reason why Sn-polymetallic mineralization has taken place in this district.
基金Item Sponsored by National Natural Science Foundation of China(51174253)
文摘Cooling process of iron ore pellets in a circular cooler has great impacts on the pellet quality and systematic energy exploitation. However, multi-variables and non-visualization of this gray system is unfavorable to efficient production. Thus, the cooling process of iron ore pellets was optimized using mathematical model and data mining techniques. A mathematical model was established and validated by steady-state production data, and the results show that the calculated values coincide very well with the measured values. Based on the proposed model, effects of important process parameters on gas-pellet temperature profiles within the circular cooler were analyzed to better understand the entire cooling process. Two data mining techniques—Association Rules Induction and Clustering were also applied on the steady-state production data to obtain expertise operating rules and optimized targets. Finally, an optimized control strategy for the circular cooler was proposed and an operation guidance system was developed. The system could realize the visualization of thermal process at steady state and provide operation guidance to optimize the circular cooler.
文摘Sheytoor Iron Ore deposit is located in Yazd province of Iran (Bafq). The most abundant ore is magnetite, which can be seen in the form of mass and granular tissue in various forms of self-shaped, semi-self-shaped and amorphous. The main purpose of this study is to identify the geochemical relationship of phosphorus and sulfur elements and also three-dimensional modeling of mineralization of these elements in iron ore. In order to achieve the research goal, methods such as k-mean clustering technique, concentration-volume fractal as well as block modeling with kriging estimator and Inverse Distance Weighting (IDW) interpolator were used. The model of geochemical behavior of phosphorus and sulfur elements compared to iron is of great importance because these two elements are known as deleterious elements in mineral processing and steelmaking processes, which are the post-mining stages. Existence of geochemical model and identification of elements’ behavior towards each other play a key role in optimizing mining operations in order to achieve geometallurgical goals. The results of this study are the three-dimensional model of mineralization of iron, phosphorus and sulfur elements, separation of phosphorus and sulfur mineralization communities and also presenting the model of enrichment community of these two elements. All the results are in line with geometallurgical studies and can optimize the next steps by optimizing the mining process.
基金Item Sponsored by National Natural Science Foundation of China(51174253)
文摘Grate-kiln-cooler has become a major process of producing iron ore pellets in China. Due to the diversity of the raw materials used and the multi-device multi-variable characteristics,this process still encounters with control problem. An attempt was proposed to deal with this issue. The three-device-integrated feature of the process was firstly analyzed to obtain control strategy,and then an intelligent control system using a combination of expert system approach and Takagi-Sugeno（ T-S） fuzzy model was developed. Expert system approach was used to diagnose and remedy the abnormal conditions,while T-S fuzzy model was used to stabilize the thermal state. In the construction of T-S fuzzy rules,antecedents were identified by fuzzy c-mean clustering algorithm incorporated with subtractive clustering algorithm,and consequent parameters were identified by recursive least square algorithm. The control system was applied in a Chinese pelletizing plant and the application results demonstrated its effectiveness of stabilizing the thermal states within three devices.
文摘The Shizhuyuan W,Sn,Mo and Bi polymetallic ore deposit is one of the world famous superlarge ore deposits.The paper briefly introduced the geological setting and features of the ore deposit.Further,an ore－ forming model was put forward at the end of the paper.
基金supported by the National Key Basic Research and Development Programme of China(No.2004CB619200)the National Science Foundation for Distinguished Young Scholars of China(No.50325415)the National Natural Science Foundation of China(No.50321402).
文摘A model GM （grey model） （1,1） for forecasting the rate of copper extraction during the bioleaching of primary sulphide ore was established on the basis of the mathematical theory and the modeling process of grey system theory. It was used for forecasting the rate of copper extraction from the primary sulfide ore during a laboratory microbial column leaching experiment. The precision of the forecasted results were examined and modified via ＂posterior variance examination＂. The results show that the forecasted values coincide with the experimental values. GM （1,1） model has high forecast accuracy; and it is suitable for simulation control and prediction analysis of the original data series of the processes that have grey characteristics, such as mining, metallurgical and mineral processing, etc. The leaching rate of such copper sulphide ore is low. The grey forecasting result indicates that the rate of copper extraction is approximately 20% even after leaching for six months.
基金Item Sponsored by National Natural Science Foundation of China(50974012)National High Technology Research and Development of China(2006AA06Z125)
文摘A model of iron ore sintering was built with consideration of fuel combustion, catalysis of sinter mixture as well as formation of melt and mineral, which was verified via sintering pot tests and showed a good fit to the experi- mental results. The effect of bed depth on temperature was reflected by the residence time in high-temperature zone, rather than the top value of the temperature, which was weakened by melt formation as well as hematite decomposi- tion. Moreover, the effect of bed depth, fuel content and distribution on sintering process was different, which was reflected by temperature profiles and the rule of calcium ferrite formation. The formation of melt as well as magnetite was a process which was decided by kinetic factors, while the formation of calcium ferrite was related to fuel blend- ing conditions, which is determined by thermodynamics when the fuel ratio inside sinter granules is low or fuel con- tent is high, otherwise, it is determined by kinetics.
文摘In the early 1980's, the author proposed his view that copper-nickel sulphide deposts are of ore magma origin. For more than ten years, this view has aroused attention of his colleagues at home and abroad. In this paper an attempt is made to deal with the genetic model for ore magma of copper-nickel sulphide deposits in more details on the basis of geological, geochemical, petrophysico - chemical and thermodynamic studies of the Chibaisong copper-nickel sulphide deposit in the Changbai Mountains, Jilin province.
基金funded by the National Natural Science Foundation of China(NSFC)(grant numbers 41472066,40972063 and 41672038)the Program of the Deep Exploration in China(SinoProb-03-05)+1 种基金the National KeyR&S Program of China(2016 YFC0600209)the Land and Resources Science and Techonolgy Foundation of Anhui Province(2016-K-03 and No.2014-K-03)
文摘The Tongling ore district is one of the most economically important ore areas in the Middle–Lower Yangtze River Metallogenic Belt, eastern China. It contains hundreds of polymetallic copper–gold deposits and occurrences. Those deposits are mainly clustered(from west to east) within the Tongguanshan, Shizishan, Xinqiao, Fenghuangshan, and Shatanjiao orefields. Until recently, the majority of these deposits were thought to be skarn-or porphyry–skarn-type deposits; however there have been recent discoveries of numerous vein-type Au, Ag, and Pb-Zn deposits that do not fall into either of these categories. This indicates that there is some uncertainty over this classification. Here, we present the results of several systematic geological studies of representative deposits in the Tongling ore district. From investigation of the ore-controlling structures, lithology of the host rock, mineral assemblages, and the characteristics of the mineralization and alteration within these deposits, three genetic types of deposits(skarn-, porphyry-, and vein-type deposits) have been identified. The spatial and temporal relationships between the orebodies and Yanshanian intrusions combined with the sources of the ore-forming fluids and metals, as well as the geodynamic setting of this ore district, indicate that all three deposit types are genetically related each other and constitute a magmatic–hydrothermal system. This study outlines a model that relates the polymetallic copper–gold porphyry-, skarn-, and vein-type deposits within the Tongling ore district. This model provides a theoretical basis to guide exploration for deep-seated and concealed porphyry-type Cu(–Mo, –Au) deposits as well as shallow vein-type Au, Ag, and Pb–Zn deposits in this area and elsewhere.
基金Sponsored by Program for New Century Excellent Talents in University of China(NCET-05-0630)
文摘Based on conduction,convection and radiation heat transfer among the flue gas,kiln wall,and the pellet bed material,and on the basis of the coal combustion and analysis of reaction heat of pellet induration in the rotary kiln,the temperature field model of rotary kiln was established.Using visual studio net,matlab and open source computer vision library as development tools,combining with the ActiveX data objects database technology,the temperature field simulation system for rotary kiln of iron ore oxidized pellet production was developed.Temperature distribution of pellet and flue gas in rotary kiln was dynamically displayed.
文摘Simulation of the direct reduction conditions was performed in a laboratory furnace. Lump samples from natural hematite iron ore were reduced by a gas mixture of H2 and CO (H2/CO =1.5) at temperatures of 700°C, 800°C and 900°C. The effect of reduction temperature on the reduction degree, reduction rate of samples and carbon deposition were investigated and discussed in this study. The thermo-gravimetric data obtained from the reduction experiments was run in a programme that calculates the solid conversion rate. Also, three models: 1) Grain Model (GM), 2) Volumetric Model (VM), and 3) the Random Pore Model (RPM), were used to estimate the reduction kinetics of natural iron ores. It was found that the RPM model result agreed best with the obtained experimental results. Furthermore, it gave better predictions of the natural iron oxide conversion and thereby the reduction kinetics.
文摘This paper presents a model derived for quantitative evaluation and prediction of the concentration of phosphorus removed during pyro-hydro beneficiation of iron oxide ore. Potassium hydroxide was used as the leaching solution and the reaction vessel containing the solution and ore was heated at a temperature of 600℃ for 10 minutes. The results of the investigation indicates that the model;P = (e0.7827) S predicts the concentration of phosphorus removed, based on the concentration of sulphur simultaneously removed. It was observed that the validity of the model is rooted in the expression lnP = lnN + lnS where both sides of the expression are approximately equal to 4. The maximum deviation of the model-predicted concentration of removed phosphorus from the corresponding concentration obtained from the experiment was less than 3%. The concentrations of phosphorus removed per unit mass-input of iron oxide ore as obtained from experiment and derived model are 0.8917 and 1.0354 mg/kg g-1 respectively. Similarly, the concentrations of phosphorus removed per unit concentration of removed sulphur as obtained from experiment and derived model are 1.8838 and 2.1874 mg/kg (mg/kg)-1 respectively. This implies that the concentration of phosphorus removed is approximately equal to the concentration of simultaneously removed sulphur during the beneficiation process.
文摘The optimization system, which was the subject of our study, is an autonomous chain for the automatic management of cyanide consumption. It is in the phase of industrial automation which made it possible to use the machines in order to reduce the workload of the worker while keeping a high productivity and a quality in great demand. Furthermore, the use of cyanide in leaching tanks is a necessity in the gold recovery process. This consumption of cyanide must be optimal in these tanks in order to have a good recovery while controlling the concentration of cyanide. Cyanide is one of the most expensive products for mining companies. On a completely different note, we see huge variations during the addition of cyanide. Following a recommendation from the metallurgical and operations teams, the control team carried out an analysis of the problem while proposing a solution to reduce the variability around plus or minus 10% of the addition setpoint through automation. It should be noted that this automatic optimization by monitoring the concentration of cyanide, made use of industrial automation which is a technique which ensures the operation of the ore processing chain without human intervention. In other words, it made it possible to substitute a machine for man. So, this leads us to conduct a study on concentration levels in the real world. The results show that the analysis of the modeling of the cyanide consumption optimization system is an appropriate solution to eradicate failures in the mineral processing chain. The trend curves demonstrate this resolution perfectly.
基金the Grand-in-Aid for Scientific Research (No. 10041136) from Ministry of Education of Japan.
文摘According to grade-tonnage diagrams of nickel and zinc deposits, their critical grades are 0.4 % and 3. 4 %, respectively, and hence the former resources can be considered optimistic and the latter pessimistic. The grade-tonnage diagram of gold deposits is convex downwards suggesting that the critical grade is 1 X 10-6 in the low-grade part. The ore value (OV)-tonnage diagram of all deposits In the world consists of three parts: high, middle and low vain f classes. The enrichment ratio (ER)-tonnage diagram of all deposits in the world ho consists of three parts: high, middle and low ratio classes.Nine quality categories defined by ER and OV are characterized by some keywords indicating deposit types as follows: category RH (high ER-high OV: 0. 7 %) by 'unconformity' and 'Mississippi Val-ley', category HM (high ER-middle: OV: 0.7 %) by 'vein', category ML (middle ER-low OV: 0 %) by 'sandstone', 'stockwork' and' dissemination', category LM by 'orthomagmatic',' laterite',komatiite and ' chemical', and category LL by 'porphyry', 'dissemination' and 'placer'. Category MM is not characterized by any keyword. If the commodities of a deposit are defined by both the enrichment ratio and the ore value, the defined commodities are relatively coincident for gold and nickel,but different for copper, silver and zinc, and greatly different for molybdenum and lead. Deposits containing lead and/or zinc are complimentary. If the commodity Ph+Zn is applied, most lead or zinc deposits are classified as Ph+Zu by both definitions. Accessory metals are commonly expected for deposits of kuroko-type zinc, epithermal silver, massive sulfide-type zinc and volcanogenic zinc, but uncommon for deposits of orthomagmatic chromium, chemically precipitated copper and sandstone-type uranium.
文摘Based on the theoretical modelling of water-rock δD-δ18O isotopic exchange process,the evolution and sources of ore-forming fluid in four metallogenic epochs of the Jinduicheng su-perlarge-scale porphyry-type molybdenum deposit were investigated. It was revealed that in thepre-metallogenic and early-metallogenic epehs, the ore-forming fluid was a residual fluid derived from magmatic water-wall rock interaction at middle to high temperatures (T = 250 -500℃) and lower W/R ratios (0. 1 > = W/R >0.001 ), while in the metallogenic and Post-metallogenic epochs, the ore-forming nuid was a residual fluid derived from meteoric water-wallrock interaction at midd1e to lower temperatures (T = 150 - 310℃ ) and relatively high W/Rratios (0. 5 >W/R≥0.1 ). The meteoric water played an important role in molybdenum min-eralization, and at the main metallogenic epoch the W/R ratio reached its maximum value.
文摘Five gold deposits (mineralization) were found in the study area by means of geologi</span><span style="font-family:Verdana;">cal mapping, soil geochemical survey and trough exploration engineering. The</span><span style="font-family:Verdana;"> ore-bearing lithology is mainly metam</span></span><span style="font-family:Verdana;">orphic feldspar sandstone of </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation, and the gold (mineralization) body is controlled by both structural factors </span><span style="font-family:Verdana;">and stratigraphic factors of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">Upper Carboniferous Benbatu Formation. The genetic</span><span style="font-family:""><span style="font-family:Verdana;"> type is preliminary concluded to be volcanic hyd</span><span style="color:black;font-family:Verdana;">rothermal type, and the metallogenic age is late Variscan. In this paper, by studying the geological characteristics and metallogenic geological conditions of the gold orebody in the area, a regional prospecting model has been established, which is of great significance to better guide the prospecting work of similar gold deposits in the area and the region.
