Ouricuri endocarp was utilized as a biosorbent for the recovery of europium(Eu(Ⅲ))from aqueous solutions and rare earth elements(REEs)from authentic leachate derived from phosphogypsum,which encompasses various REEs....Ouricuri endocarp was utilized as a biosorbent for the recovery of europium(Eu(Ⅲ))from aqueous solutions and rare earth elements(REEs)from authentic leachate derived from phosphogypsum,which encompasses various REEs.Various characterization techniques were applied to analyze the physicochemical and adsorptive properties of the biosorbent.The results indicate that the adsorption kinetic data conform well to the pseudo-first-order model,while the Liu model describes the equilibrium data well.Ouricuri endocarp and Eu interactions are favorable and spontaneous.The maximum adsorption capacity for Eu(Ⅲ)is determined to be 22.9 mg/g according to the Liu model.Based on experimental results and adsorbent characteristics,the proposed adsorption mechanisms between ouricuri endocarp and Eu include ion exchange and electrostatic interactions as the primary mechanisms.The Eu(Ⅲ)recovery is also feasible as a continuous flow process demonstrating inclined breakthrough curves and lower values of the length of the mass transfer zone.Ouricuri endocarp demonstrates its selectivity for recovering various REEs from authentic phosphogypsum leachate.It achieves a 98%recovery rate for Eu and approximately 60%for Ce,La,and Nd,affirming its efficacy under real-world conditions.Finally,concentration of REE was done by ashing loaded ouricuri endocarp,and a solid with around 34%(in weight)of REE is obtained.展开更多
A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surf...A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content, the pH value and the interfacial tension. The temperature be- fore and after ultrasonic conditioning was also investigated. The results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interracial tension and an increase in the pH value and the temperature of the pulp. The perfect index of flotation and the perfect index of desulphurization of fine coal increased by 25.19% and 18.03%, respectively, after the pulp was ultrasonically conditioned. This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation.展开更多
Exploitation and processing of pegmatoids at Brazil＇s northeast （Serido region-RN State） aiming further use as dimension stone produces mass losses ranging between 30%-90%. The tailings are predominantly composed b...Exploitation and processing of pegmatoids at Brazil＇s northeast （Serido region-RN State） aiming further use as dimension stone produces mass losses ranging between 30%-90%. The tailings are predominantly composed by feldspar, quartz, muscovite and other Fe-bearing silicates such as biotite and amphiboles, suitable for ceramic production. The recovery of these elements depends on mica＇s remotion to levels under 2.0%, preferentially by dry methods due the scarce amount of water prevailing at Serido region. This paper presents results from pegmatite tailings characterization from Serido region showing the potentially application as raw material for ceramic production. To do it, a new technological route must be developed to fit it as main component to white ceramic industry, considering the properties required by ceramic industries.展开更多
基金Project supported by the Brazilian National Council for Scientific and Technological Development/CNPq(405982/2022-4 and 303992/2021-2)。
文摘Ouricuri endocarp was utilized as a biosorbent for the recovery of europium(Eu(Ⅲ))from aqueous solutions and rare earth elements(REEs)from authentic leachate derived from phosphogypsum,which encompasses various REEs.Various characterization techniques were applied to analyze the physicochemical and adsorptive properties of the biosorbent.The results indicate that the adsorption kinetic data conform well to the pseudo-first-order model,while the Liu model describes the equilibrium data well.Ouricuri endocarp and Eu interactions are favorable and spontaneous.The maximum adsorption capacity for Eu(Ⅲ)is determined to be 22.9 mg/g according to the Liu model.Based on experimental results and adsorbent characteristics,the proposed adsorption mechanisms between ouricuri endocarp and Eu include ion exchange and electrostatic interactions as the primary mechanisms.The Eu(Ⅲ)recovery is also feasible as a continuous flow process demonstrating inclined breakthrough curves and lower values of the length of the mass transfer zone.Ouricuri endocarp demonstrates its selectivity for recovering various REEs from authentic phosphogypsum leachate.It achieves a 98%recovery rate for Eu and approximately 60%for Ce,La,and Nd,affirming its efficacy under real-world conditions.Finally,concentration of REE was done by ashing loaded ouricuri endocarp,and a solid with around 34%(in weight)of REE is obtained.
基金Projects 50274036 supported by the National Natural Science Foundation of China11531Z02 by the Educational Committee of Heilongjiang Province2009RFXXG030 by the Special Foundation of Harbin Bureau of Science and Technology
文摘A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content, the pH value and the interfacial tension. The temperature be- fore and after ultrasonic conditioning was also investigated. The results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interracial tension and an increase in the pH value and the temperature of the pulp. The perfect index of flotation and the perfect index of desulphurization of fine coal increased by 25.19% and 18.03%, respectively, after the pulp was ultrasonically conditioned. This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation.
文摘Exploitation and processing of pegmatoids at Brazil＇s northeast （Serido region-RN State） aiming further use as dimension stone produces mass losses ranging between 30%-90%. The tailings are predominantly composed by feldspar, quartz, muscovite and other Fe-bearing silicates such as biotite and amphiboles, suitable for ceramic production. The recovery of these elements depends on mica＇s remotion to levels under 2.0%, preferentially by dry methods due the scarce amount of water prevailing at Serido region. This paper presents results from pegmatite tailings characterization from Serido region showing the potentially application as raw material for ceramic production. To do it, a new technological route must be developed to fit it as main component to white ceramic industry, considering the properties required by ceramic industries.
