The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone （HA） and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentrati...The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone （HA） and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentration, anion species and temperature on zinc extraction were examined. The synergistic mechanism was discussed with regard to the structure of extractant and the extracted zinc complexes. It is found that the increase of total ammonia concentration and pH inhibits zinc extraction for all extraction systems due to the formation of zinc ammine complexes in aqueous phase. This effect of HA with CYANEX923 is evidently smaller than that of HA with LIX84I or HA alone system. Effect of anion species on the zinc extraction by HA with CYANEX923 can be neglected, but this effect of HA alone and the mixture of HA with LIX84I decreases in the order of （NH4）2SO4 〉 NH4NO3 〉 NH4Cl.展开更多
The solvent extraction of copper from simulated ammoniacal spent etchant with 1-（4＇-dodecyl）-phenyl-3-tertiary butyl-1,3-octadione（HR） was studied,and a model of extraction isotherm was proposed and verified with...The solvent extraction of copper from simulated ammoniacal spent etchant with 1-（4＇-dodecyl）-phenyl-3-tertiary butyl-1,3-octadione（HR） was studied,and a model of extraction isotherm was proposed and verified with equilibrium extraction constant.The influence of equilibration time,extractant concentration and phase ratio on the extraction of copper was studied at（298±0.5） K.For the spent etching solutions containing 112.98 g/L Cu,6 mol/L NH3 and 1 mol/L NH4＋,the optimal solvent extraction condition of copper was obtained in one-stage solvent extraction at phase ratio of 5：4 with 40% HR in sulphonated kerosene for 5 min.The copper concentration in the raffinate decreased to 63.24 g/L and raffinate can be favorably recycled to the etching solution.The stripping studies were carried out with the simulated copper spent electrolyte containing 30 g/L Cu and 180 g/L H2SO4.The stripping ratio is 98.27% from the loaded organic phase after one-stage stripping at phase ratio of 1：2 at（298±0.5） K.展开更多
This study revealed the relationship between the presence of calcium impurities and ammoniacal nitrogen concentration upon crystallization of struvite.The research hypothesis was that the presence of both calcium and ...This study revealed the relationship between the presence of calcium impurities and ammoniacal nitrogen concentration upon crystallization of struvite.The research hypothesis was that the presence of both calcium and high concentrations of ammoniacal nitrogen(328–1000 mg/L)in waste activated sludge may influence the struvite quality and acid stability.Hence,we studied the impact of Ca:Mg ratio upon morphology,particle size,purity and dissolution of struvite,in the presence of varying levels of excess ammoniacal nitrogen.X-ray diffraction revealed that up to 31.4%amorphous material was made which was assigned to hydroxyapatite.Increasing the ammoniacal nitrogen concentration and elevation of the Mg:Ca ratio maximized the presence of struvite.Struvite particle size was also increased by ammoniacal nitrogen as was twinning of the crystals.Tests with dilute solutions of organic acid revealed the sensitivity of struvite dissolution to the physical characteristics of the struvite.Smaller particles(21.2μm)dissolved at higher rates than larger particles(35.86μm).However,struvite dissolved rapidly as the p H was further reduced irrespective of the physical characteristics.Therefore,addition of struvite to low p H soils was not viewed as beneficial in terms of controlled nutrient release.Overall,this study revealed that waste activated sludge effluent with high ammoniacal nitrogen was prospective for synthesis of high quality struvite material.展开更多
The treatment of a copper sulphide-bearing gold ore by direct cyanide leaching, ammonia pretreatment and ammoniacal cyanide leaching was investigated. Dissolution behaviour of gold and copper in these leaching systems...The treatment of a copper sulphide-bearing gold ore by direct cyanide leaching, ammonia pretreatment and ammoniacal cyanide leaching was investigated. Dissolution behaviour of gold and copper in these leaching systems was demonstrated. Severe interference by the copper containing sulphides with cyanide leaching of gold is observed at p（NaCN）〈5 g/L. This is consistent with speciation calculations. Ammonia pretreatment is shown to readily eliminate the copper interference, allowing almost complete extraction of gold with concomitantly low reagent consumption in subsequent cyanide leaching. In ammoniacal cyanide system, Box-Behnken experimental design shows the main and interaction effects of NH3, NaCN and Pb（NO3）2. The concentrations of NH3 and NaCN are statistically confirmed to be significant factors affecting extraction of gold while the effect of Pb（NO3）2 is limited. Increasing the concentration of NH3 improves the selectivity and extent of gold extraction and reduces the cyanide consumption. The contribution of reagent interactions to gold extraction is statistically insignificant. These findings highlight that ammonia pretreatment and ammonia-cyanide leaching are promising approaches for the treatment of gold ores with high copper sulphide content.展开更多
Deep purification of zinc ammoniacal leaching solution by cementation using zinc dust was studied.The effects of relative amount of metallic impurities,dosage of zinc dust,purification time,temperature,pH value and to...Deep purification of zinc ammoniacal leaching solution by cementation using zinc dust was studied.The effects of relative amount of metallic impurities,dosage of zinc dust,purification time,temperature,pH value and total ammonia concentration in the solution on the purification of the solution were investigated.The results indicate that total ammonia concentration in the solution had no effect on the purification,but relative amount of metallic impurities,dosage of zinc dust,purification time,temperature and pH value of the solution were the main factors influencing the purification.Keeping appropriate molar ratio of copper to cadmium or nickel to cadmium was beneficial to the cementation of cadmium.Nevertheless,the presence of cobalt went against the cementation of cadmium and cobalt.All metallic impurities could be decreased to acceptable levels under the optimized conditions of 2 g/L of zinc dust dosage,1 h of purification time,35℃,pH value 9.03 of zinc ammoniacal leaching solution.The deeply purified zinc ammoniacal solution obtained by one-stage purification meets the requirements of zinc electrowinning.展开更多
Extraction of copper and ammonia from Cu2+-NH3-Cl--H2O solution using laboratorialy synthesized sterically hindered β-diketone(4,4-dimethyl-1-(4-dodecylphenyl)-1,3-pentanedione) was studied.The effects of the copper ...Extraction of copper and ammonia from Cu2+-NH3-Cl--H2O solution using laboratorialy synthesized sterically hindered β-diketone(4,4-dimethyl-1-(4-dodecylphenyl)-1,3-pentanedione) was studied.The effects of the copper concentration,the total ammonia concentration,the initial pH in the aqueous phase,the phase ratio,and the temperature on copper extraction ratio and ammonia extraction in loaded organic phase were investigated using this sterically hindered β-diketone.Under the conditions of temperature 25℃,contact time of two phases 30 min,phase ratio 1-1,concentration of copper 3 g/L,concentration of total ammonia 3 mol/L,aqueous pH 8.43,and the concentration of β-diketone in organic phase 20%(volume fraction),ammonia in aqueous phase is much lower to be extracted by organic phase(just 14.5 mg/L),while the extraction rate of copper is 95.09%.展开更多
The zinc-containing dust was oxidatively pretreated with calcium hypochlorite,subsequently leached with ammonia/ammonium bicarbonate solution to obtain the ammoniacal leaching solution,and zinc oxide was produced by a...The zinc-containing dust was oxidatively pretreated with calcium hypochlorite,subsequently leached with ammonia/ammonium bicarbonate solution to obtain the ammoniacal leaching solution,and zinc oxide was produced by ammonia distillation of the ammoniacal leaching solution and subsequent calcination. The elements of iron and manganese could not be detected in ammoniacal leaching solution,and the extraction rate of zinc was 98.2% in ammoniacal leaching process. The zinc oxide content in the product is 99.5%(ω),and the contents of iron and manganese in the product were 0.002 8‰ and 0.000 84‰(ω), respectively. The analyses of the valence states of iron and manganese in the zinc-containing dust with and without pretreatment were performed by chemical analysis and XPS,and the possible oxidation mechanism of the oxidative pretreatment of the dust was discussed. It is concluded that Fe 2+-oxide and Mn 2+-oxide in the dust were oxidized to Fe 3+-oxide and/or its hydrate and Mn 4+-oxide and/or its hydrate by calcium hypochlorite during the oxidative pretreatment process,respectively.展开更多
Ammoniacal thiosulfate solutions with cupric ions have proved to be more successful than cyanidation in handling complex ores like carbonaceous and cuprous minerals. That＇s why cyanidation and ammoniacal thiosulfate ...Ammoniacal thiosulfate solutions with cupric ions have proved to be more successful than cyanidation in handling complex ores like carbonaceous and cuprous minerals. That＇s why cyanidation and ammoniacal thiosulfate leaching was performed at 33% of solids concentration in order to compare the efficiency of both techniques. Cyanidation delivered a gold recovery of 80.6% at 24 hours of agitation, whereas ammoniacal thiosulfate leaching achieved an 80.9% of gold recovery in only one hour of agitation. Then, the ammoniacal thiosulfate solutions obtained were submitted to five gold recovery techniques （carbon adsorption, cementation, adsorption on carbon impregnated with metallic copper, ion flotation and electrolysis） in order to determine which one of them was the most effective technique. Ion flotation proved to be the best technique due to its gold recovery of 84%. In addition, this technique only required trioctyl methyl ammonium chloride （Aliquat） and FloMin F-121 in a 0.1% concentration inside the solution. The small amounts of the flotation reagents allow the flotation concentrate to be treated by electrolysis. It was performed with 1.5 V during three hours and the resulting gold recovery was 82% in the cathode zone.展开更多
Objective:To study the effect of sal ammoniac extract on the treatment of liver cancer and analyze its possibility of replacing absolute ethanol.Methods:Sixty Kunming mice(5-6 weeks old,18-22g in weight,male and femal...Objective:To study the effect of sal ammoniac extract on the treatment of liver cancer and analyze its possibility of replacing absolute ethanol.Methods:Sixty Kunming mice(5-6 weeks old,18-22g in weight,male and female in half)were selected and inoculated with 0.1 ml of 1:4 ascitic diluent from mouse liver cancer H22 under the axilla of the right limb.After tumor formation,they were randomly divided into 3 groups with 20 mice in each group.Normal saline(NS),sal ammoniac extract(N),and absolute ethanol(E)were injected into the tumor once a day for four times.The death,tumor weight,tumor inhibition rate,lactate dehydrogenase(LDH),and succinate dehydrogenase(SDH)expression of the mice in each group were analyzed.Results:In the course of treatment,3 mice died in the normal saline group,2 mice died in the sal ammoniac treatment group,and 7 mice died in the absolute ethanol group.The tumor weight of the normal saline group,sal ammoniac treatment group,and absolute ethanol group were 1.880.26,1.41±0.49,and 1.51±0.46,respectively.The tumor inhibition rates were 0%,31.0%,and 21.6%,respectively.Comparing the sal ammoniac treatment group and the normal saline group,t=3.5133,p=0.0013;comparing the absolute ethanol group and the normal saline group,t=2.7926,p=0.0093.The expression of LDH was 81±10,51±11,and 32±9 in the normal saline group,sal ammoniac treatment group,and absolute ethanol group,respectively,while the expression of SDH was 80±10,5110,and 51±12 in the normal saline group,sal ammoniac treatment group,and absolute ethanol group,respectively.Comparing the LDH of the sal ammoniac treatment group with that of the saline group,t=8.4264,ρ=0.0000;comparing the absolute ethanol group and normal saline group,t=13.8763,p=0.0000.Comparing the SDH of the sal ammoniac treatment group with that of the normal saline group,t=8.1455,ρ=0.0000;comparing the absolute ethanol group with the normal saline group,t=7.2197,ρ=0.0000.Conclusion:The traditional Chinese antitumor medicine,sal ammoniac and its main effective components have good antitumor effect,which can be further popularized and applied in clinical practice.展开更多
Anodic dissolution of arsenopyrite in ammoniacal solution has been investigated by electrochemical methods. The process is an irreversible reaction with formation of a ferric oxidized film and is retarded by the film....Anodic dissolution of arsenopyrite in ammoniacal solution has been investigated by electrochemical methods. The process is an irreversible reaction with formation of a ferric oxidized film and is retarded by the film. The process rate is controlled by the electrochemical reaction on the electrode surface in the lower temperature range, or alternatively by the diffusion through the film in the higher temperature range. The overall reaction has 14 electron transferred and can be expressed by FeAsS + 11H2O = Fe(OH)3 + SO42- + HAsO42- + 18H+ + 14e-, and the reaction involves two steps: (1) FeAsS + 7H2O = Fe(OH)3 + HAsO42- + S0 + 10H+ + 8e- , (2) S0 + 4H2O = SO42- + 8H+ + 6e- .展开更多
To provide optimization strategies for chalcopyrite ammonia heap leaching processes,the key factors influencing chalcopyrite ammonia leaching kinetics were investigated under sealed reactor and controlled redox potent...To provide optimization strategies for chalcopyrite ammonia heap leaching processes,the key factors influencing chalcopyrite ammonia leaching kinetics were investigated under sealed reactor and controlled redox potential at ambient temperature.The results indicated that redox potential,particle size,and pH significantly affected chalcopyrite dissolution rates.The reaction orders with respect to particle size and hydroxyl ion concentration c(OH−)were determined to be−2.39 and 0.55,respectively.Temperature exhibited a marginal effect on chalcopyrite dissolution within the range of 25−45℃.The ammonium carbonate medium proved more favorable for chalcopyrite leaching than ammonium chloride and ammonium sulfate systems.Surface deposits on the residues were identified as porous iron oxides,predominantly hematite and ferrihydrite,which produced diffusion barriers during leaching.Shrinking core model analysis revealed that the second stage of reaction was controlled by product-layer diffusion,which was further confirmed by the low activation energy(10.18 kJ/mol).展开更多
The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentratio...The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentrations of ammonia, ammonium sulfate and sodium persulfate were determined. The results show that the leaching rate is nearly independent of agitation above 300 r/min and increases with the increase of temperature, concentrations of ammonia, ammonium sulfate and sodium persulfate. The EDS analysis and phase quantitative analysis of the residues indicate that bornite can be dissolved by persulfate oxidization. The leaching kinetics with activation energy of 22.91 kJ/mol was analyzed by using a new shrinking core model （SCM） in which both the interfacial transfer and diffusion across the product layer affect the leaching rate. A semi-empirical rate equation was obtained to describe the leaching process and the empirical reaction orders with respect to the concentrations of ammonia, ammonium sulfate and sodium persulfate are 0.5, 1.2 and 0.5, respectively.展开更多
基金Project (2007CB613601) supported by the National Basic Research Program of ChinaProject (CX2010B112) supported by Hunan Provincial Innovation Foundation for Postgraduate, China
文摘The extraction behaviors of zinc from ammoniacal solutions were investigated using β-diketone （HA） and their mixtures with CYANEX923 or LIX84I. The effects of pH, total ammonia concentration, extractant concentration, anion species and temperature on zinc extraction were examined. The synergistic mechanism was discussed with regard to the structure of extractant and the extracted zinc complexes. It is found that the increase of total ammonia concentration and pH inhibits zinc extraction for all extraction systems due to the formation of zinc ammine complexes in aqueous phase. This effect of HA with CYANEX923 is evidently smaller than that of HA with LIX84I or HA alone system. Effect of anion species on the zinc extraction by HA with CYANEX923 can be neglected, but this effect of HA alone and the mixture of HA with LIX84I decreases in the order of （NH4）2SO4 〉 NH4NO3 〉 NH4Cl.
基金Project (2007CB613601) supported by the National Basic Research Program of China
文摘The solvent extraction of copper from simulated ammoniacal spent etchant with 1-（4＇-dodecyl）-phenyl-3-tertiary butyl-1,3-octadione（HR） was studied,and a model of extraction isotherm was proposed and verified with equilibrium extraction constant.The influence of equilibration time,extractant concentration and phase ratio on the extraction of copper was studied at（298±0.5） K.For the spent etching solutions containing 112.98 g/L Cu,6 mol/L NH3 and 1 mol/L NH4＋,the optimal solvent extraction condition of copper was obtained in one-stage solvent extraction at phase ratio of 5：4 with 40% HR in sulphonated kerosene for 5 min.The copper concentration in the raffinate decreased to 63.24 g/L and raffinate can be favorably recycled to the etching solution.The stripping studies were carried out with the simulated copper spent electrolyte containing 30 g/L Cu and 180 g/L H2SO4.The stripping ratio is 98.27% from the loaded organic phase after one-stage stripping at phase ratio of 1：2 at（298±0.5） K.
基金funded through the financial support of “Australian Government Research Training Program (RTP) Stipend”supported by generous funding from the Science and Engineering Faculty (SEF-QUT)
文摘This study revealed the relationship between the presence of calcium impurities and ammoniacal nitrogen concentration upon crystallization of struvite.The research hypothesis was that the presence of both calcium and high concentrations of ammoniacal nitrogen(328–1000 mg/L)in waste activated sludge may influence the struvite quality and acid stability.Hence,we studied the impact of Ca:Mg ratio upon morphology,particle size,purity and dissolution of struvite,in the presence of varying levels of excess ammoniacal nitrogen.X-ray diffraction revealed that up to 31.4%amorphous material was made which was assigned to hydroxyapatite.Increasing the ammoniacal nitrogen concentration and elevation of the Mg:Ca ratio maximized the presence of struvite.Struvite particle size was also increased by ammoniacal nitrogen as was twinning of the crystals.Tests with dilute solutions of organic acid revealed the sensitivity of struvite dissolution to the physical characteristics of the struvite.Smaller particles(21.2μm)dissolved at higher rates than larger particles(35.86μm).However,struvite dissolved rapidly as the p H was further reduced irrespective of the physical characteristics.Therefore,addition of struvite to low p H soils was not viewed as beneficial in terms of controlled nutrient release.Overall,this study revealed that waste activated sludge effluent with high ammoniacal nitrogen was prospective for synthesis of high quality struvite material.
基金The Scientific and Technological Research Council of Turkey (TUBITAK) for providing financial support via a S&T research project (Project No. 213M492)
文摘The treatment of a copper sulphide-bearing gold ore by direct cyanide leaching, ammonia pretreatment and ammoniacal cyanide leaching was investigated. Dissolution behaviour of gold and copper in these leaching systems was demonstrated. Severe interference by the copper containing sulphides with cyanide leaching of gold is observed at p（NaCN）〈5 g/L. This is consistent with speciation calculations. Ammonia pretreatment is shown to readily eliminate the copper interference, allowing almost complete extraction of gold with concomitantly low reagent consumption in subsequent cyanide leaching. In ammoniacal cyanide system, Box-Behnken experimental design shows the main and interaction effects of NH3, NaCN and Pb（NO3）2. The concentrations of NH3 and NaCN are statistically confirmed to be significant factors affecting extraction of gold while the effect of Pb（NO3）2 is limited. Increasing the concentration of NH3 improves the selectivity and extent of gold extraction and reduces the cyanide consumption. The contribution of reagent interactions to gold extraction is statistically insignificant. These findings highlight that ammonia pretreatment and ammonia-cyanide leaching are promising approaches for the treatment of gold ores with high copper sulphide content.
基金Supported by the National Basic Research Program of China (973 Project) (No.2007CB613601)
文摘Deep purification of zinc ammoniacal leaching solution by cementation using zinc dust was studied.The effects of relative amount of metallic impurities,dosage of zinc dust,purification time,temperature,pH value and total ammonia concentration in the solution on the purification of the solution were investigated.The results indicate that total ammonia concentration in the solution had no effect on the purification,but relative amount of metallic impurities,dosage of zinc dust,purification time,temperature and pH value of the solution were the main factors influencing the purification.Keeping appropriate molar ratio of copper to cadmium or nickel to cadmium was beneficial to the cementation of cadmium.Nevertheless,the presence of cobalt went against the cementation of cadmium and cobalt.All metallic impurities could be decreased to acceptable levels under the optimized conditions of 2 g/L of zinc dust dosage,1 h of purification time,35℃,pH value 9.03 of zinc ammoniacal leaching solution.The deeply purified zinc ammoniacal solution obtained by one-stage purification meets the requirements of zinc electrowinning.
基金Project(2007CB613601) supported by the National Basic Research Program of ChinaProject(NCET-08) supported by Program for New Century Excellent Talents in University, China
文摘Extraction of copper and ammonia from Cu2+-NH3-Cl--H2O solution using laboratorialy synthesized sterically hindered β-diketone(4,4-dimethyl-1-(4-dodecylphenyl)-1,3-pentanedione) was studied.The effects of the copper concentration,the total ammonia concentration,the initial pH in the aqueous phase,the phase ratio,and the temperature on copper extraction ratio and ammonia extraction in loaded organic phase were investigated using this sterically hindered β-diketone.Under the conditions of temperature 25℃,contact time of two phases 30 min,phase ratio 1-1,concentration of copper 3 g/L,concentration of total ammonia 3 mol/L,aqueous pH 8.43,and the concentration of β-diketone in organic phase 20%(volume fraction),ammonia in aqueous phase is much lower to be extracted by organic phase(just 14.5 mg/L),while the extraction rate of copper is 95.09%.
基金Supported by the National Basic Research Program of China(973)(No.2007CB613601)Supported by the National Natural Science Foundationof China(No.51134007)Supported by the Science&Technology Plan of Hunan Province(No.2011FJ6005)
文摘The zinc-containing dust was oxidatively pretreated with calcium hypochlorite,subsequently leached with ammonia/ammonium bicarbonate solution to obtain the ammoniacal leaching solution,and zinc oxide was produced by ammonia distillation of the ammoniacal leaching solution and subsequent calcination. The elements of iron and manganese could not be detected in ammoniacal leaching solution,and the extraction rate of zinc was 98.2% in ammoniacal leaching process. The zinc oxide content in the product is 99.5%(ω),and the contents of iron and manganese in the product were 0.002 8‰ and 0.000 84‰(ω), respectively. The analyses of the valence states of iron and manganese in the zinc-containing dust with and without pretreatment were performed by chemical analysis and XPS,and the possible oxidation mechanism of the oxidative pretreatment of the dust was discussed. It is concluded that Fe 2+-oxide and Mn 2+-oxide in the dust were oxidized to Fe 3+-oxide and/or its hydrate and Mn 4+-oxide and/or its hydrate by calcium hypochlorite during the oxidative pretreatment process,respectively.
文摘Ammoniacal thiosulfate solutions with cupric ions have proved to be more successful than cyanidation in handling complex ores like carbonaceous and cuprous minerals. That＇s why cyanidation and ammoniacal thiosulfate leaching was performed at 33% of solids concentration in order to compare the efficiency of both techniques. Cyanidation delivered a gold recovery of 80.6% at 24 hours of agitation, whereas ammoniacal thiosulfate leaching achieved an 80.9% of gold recovery in only one hour of agitation. Then, the ammoniacal thiosulfate solutions obtained were submitted to five gold recovery techniques （carbon adsorption, cementation, adsorption on carbon impregnated with metallic copper, ion flotation and electrolysis） in order to determine which one of them was the most effective technique. Ion flotation proved to be the best technique due to its gold recovery of 84%. In addition, this technique only required trioctyl methyl ammonium chloride （Aliquat） and FloMin F-121 in a 0.1% concentration inside the solution. The small amounts of the flotation reagents allow the flotation concentrate to be treated by electrolysis. It was performed with 1.5 V during three hours and the resulting gold recovery was 82% in the cathode zone.
基金This research was supported by the General and Special Scientific Research Project of the Education Department of Shaanxi Province(Project Number:20JK0887):Molecular Mechanism of MiR-122 Competitive Endogenous LncRNA in the Development of Liver Cancer.
文摘Objective:To study the effect of sal ammoniac extract on the treatment of liver cancer and analyze its possibility of replacing absolute ethanol.Methods:Sixty Kunming mice(5-6 weeks old,18-22g in weight,male and female in half)were selected and inoculated with 0.1 ml of 1:4 ascitic diluent from mouse liver cancer H22 under the axilla of the right limb.After tumor formation,they were randomly divided into 3 groups with 20 mice in each group.Normal saline(NS),sal ammoniac extract(N),and absolute ethanol(E)were injected into the tumor once a day for four times.The death,tumor weight,tumor inhibition rate,lactate dehydrogenase(LDH),and succinate dehydrogenase(SDH)expression of the mice in each group were analyzed.Results:In the course of treatment,3 mice died in the normal saline group,2 mice died in the sal ammoniac treatment group,and 7 mice died in the absolute ethanol group.The tumor weight of the normal saline group,sal ammoniac treatment group,and absolute ethanol group were 1.880.26,1.41±0.49,and 1.51±0.46,respectively.The tumor inhibition rates were 0%,31.0%,and 21.6%,respectively.Comparing the sal ammoniac treatment group and the normal saline group,t=3.5133,p=0.0013;comparing the absolute ethanol group and the normal saline group,t=2.7926,p=0.0093.The expression of LDH was 81±10,51±11,and 32±9 in the normal saline group,sal ammoniac treatment group,and absolute ethanol group,respectively,while the expression of SDH was 80±10,5110,and 51±12 in the normal saline group,sal ammoniac treatment group,and absolute ethanol group,respectively.Comparing the LDH of the sal ammoniac treatment group with that of the saline group,t=8.4264,ρ=0.0000;comparing the absolute ethanol group and normal saline group,t=13.8763,p=0.0000.Comparing the SDH of the sal ammoniac treatment group with that of the normal saline group,t=8.1455,ρ=0.0000;comparing the absolute ethanol group with the normal saline group,t=7.2197,ρ=0.0000.Conclusion:The traditional Chinese antitumor medicine,sal ammoniac and its main effective components have good antitumor effect,which can be further popularized and applied in clinical practice.
基金Supported by the National Natural Science Foundation of China (No.: 59674023)
文摘Anodic dissolution of arsenopyrite in ammoniacal solution has been investigated by electrochemical methods. The process is an irreversible reaction with formation of a ferric oxidized film and is retarded by the film. The process rate is controlled by the electrochemical reaction on the electrode surface in the lower temperature range, or alternatively by the diffusion through the film in the higher temperature range. The overall reaction has 14 electron transferred and can be expressed by FeAsS + 11H2O = Fe(OH)3 + SO42- + HAsO42- + 18H+ + 14e-, and the reaction involves two steps: (1) FeAsS + 7H2O = Fe(OH)3 + HAsO42- + S0 + 10H+ + 8e- , (2) S0 + 4H2O = SO42- + 8H+ + 6e- .
基金the financial supports from the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA0430304).
文摘To provide optimization strategies for chalcopyrite ammonia heap leaching processes,the key factors influencing chalcopyrite ammonia leaching kinetics were investigated under sealed reactor and controlled redox potential at ambient temperature.The results indicated that redox potential,particle size,and pH significantly affected chalcopyrite dissolution rates.The reaction orders with respect to particle size and hydroxyl ion concentration c(OH−)were determined to be−2.39 and 0.55,respectively.Temperature exhibited a marginal effect on chalcopyrite dissolution within the range of 25−45℃.The ammonium carbonate medium proved more favorable for chalcopyrite leaching than ammonium chloride and ammonium sulfate systems.Surface deposits on the residues were identified as porous iron oxides,predominantly hematite and ferrihydrite,which produced diffusion barriers during leaching.Shrinking core model analysis revealed that the second stage of reaction was controlled by product-layer diffusion,which was further confirmed by the low activation energy(10.18 kJ/mol).
基金Project(2007CB613601)supported by the National Basic Research Program of ChinaProject(10C1095)supported by the Foundation of Hunan Educational Committee,China
文摘The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentrations of ammonia, ammonium sulfate and sodium persulfate were determined. The results show that the leaching rate is nearly independent of agitation above 300 r/min and increases with the increase of temperature, concentrations of ammonia, ammonium sulfate and sodium persulfate. The EDS analysis and phase quantitative analysis of the residues indicate that bornite can be dissolved by persulfate oxidization. The leaching kinetics with activation energy of 22.91 kJ/mol was analyzed by using a new shrinking core model （SCM） in which both the interfacial transfer and diffusion across the product layer affect the leaching rate. A semi-empirical rate equation was obtained to describe the leaching process and the empirical reaction orders with respect to the concentrations of ammonia, ammonium sulfate and sodium persulfate are 0.5, 1.2 and 0.5, respectively.
