In flotation,metal ions possess significant roles that are usually fulfilled by either selectively activating or depressing the target minerals.Despite that tremendous efforts have been made to address the roles of me...In flotation,metal ions possess significant roles that are usually fulfilled by either selectively activating or depressing the target minerals.Despite that tremendous efforts have been made to address the roles of metal ions in flotation,it still lacks a comprehensive review,especially to compare various ions instead of focusing on a specific one.This review begins by elaborately categorizing the factors involved in affecting the roles of metal ions in flotation.After that,well-accepted mechanisms are updated and discussed from the ore type.Furthermore,typical approaches to explore the underlying mechanisms are emphasized,including traditional techniques such as micro-flotation,contact angle measurement,zeta potential measurement,and other recent prevailing methodologies,like computational method,solution chemistry calculation,and cyclic voltammetry.This work will pave the way to promote flotations via activities like selectively adding/reducing metal ions,choosing reagents,and regulating the slurry chemistry.展开更多
Low-cost adsorbents constituted by Fe-modified-aluminosilicates (laminar and zeolite type minerals) were developed and characterized to be used in the arsenic removal from groundwater. Iron activation was carried o...Low-cost adsorbents constituted by Fe-modified-aluminosilicates (laminar and zeolite type minerals) were developed and characterized to be used in the arsenic removal from groundwater. Iron activation was carried out "in situ" by the synthesis and deposition of mesoporous ferrihydrite. Natural iron-rich aluminosilicate was used as reference. All samples were characterized by X-ray diffraction, Raman spectroscopy, BET N2-adsorption, SEM-EDS microscopy and ICP chemical analysis. Experimental results of arsenic sorption showed that iron-poor raw materials were not active, unlike iron activated samples. The iron loading in all activated samples was below 5% (expressed as Fe203), whereas the removal capacity of these samples reaches between 200-700 gg of As by g of adsorbent, after reusing between 17 cycles and 70 cycles up to adsorbent saturation. Differences can be associated to mineral structure and to the surface charge modification by iron deposition, affecting the attraction of the As-oxoanion. On the basis of low-cost raw materials, the easy chemical process for activation shows that these materials are potentially attractive for As(V) removal. Likewise, the activation of clay minerals, with natural high content of iron, seems to be a good strategy to enhance the arsenic adsorption ability and consequently the useful life of the adsorbent.展开更多
The structural changes of silicate anions in the desilication process with the addition of calcium hydrate alumino-carbonate were studied by measuring Raman spectra, infrared spectra and corresponding second derivativ...The structural changes of silicate anions in the desilication process with the addition of calcium hydrate alumino-carbonate were studied by measuring Raman spectra, infrared spectra and corresponding second derivative spectra. The results show that the desilication ratio in the solution prepared by the addition of sodium silicate(solution-SS) is much greater than that in the solution by the addition of green liquor(solution-GL), and low alumina concentration in the sodium aluminate solutions facilitates the desilication process. It is also shown that alumino-silicate anions in the solution-GL, and Q^3 polymeric silicate anions in solution-SS are predominant, respectively. In addition, increasing the concentration of silica favors respectively the formation of the alumino-silicate or the Q^3 silicate anions in the solution-GL or the solution-SS. Therefore, it can be inferred that the low desilication ratio in the silicate-bearing aluminate solution is mainly attributed to the existence of alumino-silicate anions.展开更多
For Finland, carbon dioxide mineralisation was identified as the only option for CCS (carbon capture and storage) application. Unfortunately it has not been embraced by the power sector. One interesting source-sink ...For Finland, carbon dioxide mineralisation was identified as the only option for CCS (carbon capture and storage) application. Unfortunately it has not been embraced by the power sector. One interesting source-sink combination, however, is formed by magnesium silicate resources at Vammala, located -85 km east of the 565 MWe coal-fired Meri-Pori Power Plant on the country's southwest coast. This paper assesses mineral sequestration of Meri-Pori power plant CO2, using Vammala mineral resources and the mineralisation process under development at Abo Akademi University. That process implies Mg(OH)E production from magnesium silicate-based rock, followed by gas/solid carbonation of the Mg(OH)2 in a pressurised fluidised bed. Reported are results on experimental work, i.e., Mg(OH)2 production, with rock from locations close to Meri-Pori. Results suggest a total CO2 fixation capacity -50 Mt CO2 for the Vammala site, although production of Mg(OH)2 from rock from the site is challenging. Finally, as mineralisation could be directly applied to flue gases without CO2 pre-capture, we report from experimental work on carbonation of Mg(OH)2 with CO2 and CO2-SO2-O2 gas mixtures. Results show that SO2 readily reacts with Mg(OH)2, providing an opportunity to simultaneously capture SO2 and CO2, which could make separate flue gas desulphurisation redundant.展开更多
基金financial supports from the National Natural Science Foundation of China(Nos.U2067201,51774328)the Key Program for International S&T Cooperation Projects of China(No.2021YFE0106800)+2 种基金the Science Fund for Distinguished Young Scholars of Hunan Province,China(No.2020JJ2044)the Young Elite Scientists Sponsorship Program by Hunan province of China(No.2018RS3011)the National 111 Project of China(No.B14034)。
文摘In flotation,metal ions possess significant roles that are usually fulfilled by either selectively activating or depressing the target minerals.Despite that tremendous efforts have been made to address the roles of metal ions in flotation,it still lacks a comprehensive review,especially to compare various ions instead of focusing on a specific one.This review begins by elaborately categorizing the factors involved in affecting the roles of metal ions in flotation.After that,well-accepted mechanisms are updated and discussed from the ore type.Furthermore,typical approaches to explore the underlying mechanisms are emphasized,including traditional techniques such as micro-flotation,contact angle measurement,zeta potential measurement,and other recent prevailing methodologies,like computational method,solution chemistry calculation,and cyclic voltammetry.This work will pave the way to promote flotations via activities like selectively adding/reducing metal ions,choosing reagents,and regulating the slurry chemistry.
文摘Low-cost adsorbents constituted by Fe-modified-aluminosilicates (laminar and zeolite type minerals) were developed and characterized to be used in the arsenic removal from groundwater. Iron activation was carried out "in situ" by the synthesis and deposition of mesoporous ferrihydrite. Natural iron-rich aluminosilicate was used as reference. All samples were characterized by X-ray diffraction, Raman spectroscopy, BET N2-adsorption, SEM-EDS microscopy and ICP chemical analysis. Experimental results of arsenic sorption showed that iron-poor raw materials were not active, unlike iron activated samples. The iron loading in all activated samples was below 5% (expressed as Fe203), whereas the removal capacity of these samples reaches between 200-700 gg of As by g of adsorbent, after reusing between 17 cycles and 70 cycles up to adsorbent saturation. Differences can be associated to mineral structure and to the surface charge modification by iron deposition, affecting the attraction of the As-oxoanion. On the basis of low-cost raw materials, the easy chemical process for activation shows that these materials are potentially attractive for As(V) removal. Likewise, the activation of clay minerals, with natural high content of iron, seems to be a good strategy to enhance the arsenic adsorption ability and consequently the useful life of the adsorbent.
基金Project(51274242)supported by the National Natural Science Foundation of ChinaProject(2015CX001)supported by the Innovation-driven Plan in Central South University,China
文摘The structural changes of silicate anions in the desilication process with the addition of calcium hydrate alumino-carbonate were studied by measuring Raman spectra, infrared spectra and corresponding second derivative spectra. The results show that the desilication ratio in the solution prepared by the addition of sodium silicate(solution-SS) is much greater than that in the solution by the addition of green liquor(solution-GL), and low alumina concentration in the sodium aluminate solutions facilitates the desilication process. It is also shown that alumino-silicate anions in the solution-GL, and Q^3 polymeric silicate anions in solution-SS are predominant, respectively. In addition, increasing the concentration of silica favors respectively the formation of the alumino-silicate or the Q^3 silicate anions in the solution-GL or the solution-SS. Therefore, it can be inferred that the low desilication ratio in the silicate-bearing aluminate solution is mainly attributed to the existence of alumino-silicate anions.
文摘For Finland, carbon dioxide mineralisation was identified as the only option for CCS (carbon capture and storage) application. Unfortunately it has not been embraced by the power sector. One interesting source-sink combination, however, is formed by magnesium silicate resources at Vammala, located -85 km east of the 565 MWe coal-fired Meri-Pori Power Plant on the country's southwest coast. This paper assesses mineral sequestration of Meri-Pori power plant CO2, using Vammala mineral resources and the mineralisation process under development at Abo Akademi University. That process implies Mg(OH)E production from magnesium silicate-based rock, followed by gas/solid carbonation of the Mg(OH)2 in a pressurised fluidised bed. Reported are results on experimental work, i.e., Mg(OH)2 production, with rock from locations close to Meri-Pori. Results suggest a total CO2 fixation capacity -50 Mt CO2 for the Vammala site, although production of Mg(OH)2 from rock from the site is challenging. Finally, as mineralisation could be directly applied to flue gases without CO2 pre-capture, we report from experimental work on carbonation of Mg(OH)2 with CO2 and CO2-SO2-O2 gas mixtures. Results show that SO2 readily reacts with Mg(OH)2, providing an opportunity to simultaneously capture SO2 and CO2, which could make separate flue gas desulphurisation redundant.