Dissolution of multicomponents during hydrothermal leaching of LF desulfurization slag

In light of the multicomponent dissolution equilibrium during the hydrothermal leaching of LF desulfurization slag, thermodynamic calculations were made and the dissolution equilibrium curves of calcium, aluminum and sulfur were plotted to analyze the interactions between these components and their influence on sulfur leaching. Furthermore, slag leaching experiments were conducted to investigate variation of pH and concentration of major components in the leaching solution. The results show that CaS(s) is easily soluble in water, and when pH>11. 4, CaS(s) dissolves to form Ca(OH)2(s). Use of hydrothermal leaching for sulfur removal from LF desulfurization slag is theoretically feasible. CaSO4(s) is difficult to dissolve and its solubility is always lower than that of CaS(s); therefore, slag oxidation affects negatively sulfur leaching. However, when the pH of the leaching environment is controlled to be above 12. 3, CaSO4(s) is gradually transformed into Ca(OH)2(s). Al2(SO4)3(s) is easily soluble, and it is unlikely that Al will react with sulfur in the solution to form a precipitate. The pH of the leaching solution rises with time and remains at about 12. Calcium concentration in the leaching solution is high, while Al concentration is low. Sulfur concentration in the solution increases with time, and Al in the slag has little effect on sulfur leaching. It is thus concluded that hydrothermal leaching is effective in removing sulfur from LF desulfurization slag.     

氯化亚铁在氯化尾气淋洗中的应用研究

氯化亚铁溶液因其制备工艺简单，原料价格低廉等，被作为还原剂广泛应用于化工领域和冶金领域。试验主要应用其易与氯气发生化学反应的特点，创新地应用到氯化生产中的尾气治理方面，有效解决因长期依赖碱液淋洗尾气带来的管道堵塞现象及二次污染等问题。     

镍蛇纹石浸出试验研究

采用内蒙某地的镍蛇纹石矿粉为原料,对硫酸浸出工艺进行了系统的条件试验研究,并得出结论:在磨矿细度为-100目95%、硫酸用量(过量)20%时,MgO浸出率相对变化较大,具有较好的浸出率,从而在此最佳的试验条件参数下,进行了半工业试验,为工业生产提供依据。     

Fabrication of PLGA Based Tissue Engineering Scaffolds via Photocuring and Salt Leaching Techniques

The authors aimed to prepare UV curable porous scaffolds via photo curing and salt leaching techniques. A poly (α -hydroxy ester) based urethane acrylate oligomer was synthesized and a photocurable acrylic based formulation was prepared. Salt particles were introduced to the formulation, which was then poured into cylindrical molds and cured under UV irradiation. Porous scaffolds were obtained after salt leaching. 3T3 cells seeded on the UV cured scaffolds and it was found that cells were well spread on the collagen modified scaffold surface. It can be concluded that the scaffolds provided an effective physical support that allows cell adhesion and proliferation.     

Migration and distribution of saline ions in bauxite residue during water leaching

Bauxite residue, a highly saline solid waste produced from digestion of bauxite for alumina production, is hazardous to the environment and restricts vegetation establishment in bauxite residue disposal areas. A novel water leaching process proposed here was used to investigate the dynamic migration and vertical distribution of saline ions in bauxite residue. The results show that water leaching significantly reduced the salinity of bauxite residue, leaching both saline cations Na⁺, K⁺, Ca²⁺ and anions CO^2?₃, SO^2?₄, HCO^?₃. Na⁺ and K⁺ migrated from 40–50 to 20–30 cm of the column, presenting a high migration capacity. The migration capacity of Ca²⁺ was lower and accumulated at 30–40 cm of the column. CO^2?₃ initially distributed at 20–30 cm of the column, subsequently transported to 30–40 cm of the column, and finally returned to 20–30 cm of the column along with evaporation. SO^2?₄ was originally distributed at 40–50 cm, but finally migrated to 20–30 cm of the column. Nevertheless, HCO^?₃ remained at the bottom of the column, and its migratory was less affected by evaporation.     

Management scenarios for olive oil mill waste based on characterization and leaching tests

BACKGROUND: Olive oil mill waste is a serious environmental problem in the Mediterranean basin given its particular characteristics of high organic content, seasonal and localized generation, and the type of processing involved. RESULTS: Olive mill waste from a three‐phase mill was characterized by means of total analysis, availability and mobility of the pollutants in order to help the decision‐maker about possible options for its valorization and/or disposal. Water content, loss of ignition, total organic carbon, phenol index and metals concentrations were measured to fully characterize the waste. Three leaching tests (NEN 7341, EN 12457 and UNE CEN‐TS 15364 EX) were carried out to evaluate the environmental hazard of the waste material and the leachates were characterized with respect to electric conductivity, pH, heavy metals, anions and organic pollutants (phenol index and total organic carbon) according to European waste directives. The results were compared with EU regulations for inert, non‐hazardous and hazardous waste disposal. CONCLUSION: It was found that not only organic parameters must be taken into account concerning the fate of this waste material, but also the mobility of heavy metals and anions should be studied. Furthermore, stabilization/solidification processes are recommended before landfill disposal of this kind of agro‐waste material. Copyright © 2011 Society of Chemical Industry     

微波选择性加热在矿冶过程中的应用进展

微波由于其特殊的能量传递和转换方式,作为一种绿色的加热方式已经被广泛应用于工业生产。概述了微波加热原理和作用参数,从研究手段、处理过程和应用成果等方面评述了近几年来微波选择性加热在辅助磨矿、强化还原以及辅助浸出等冶金过程应用中的最新进展;最后提出了其存在的问题并展望了应用前景。     

油页岩制油残渣制备氧化铝及其铝浸出率的研究

以抚顺东露天油页岩制油残渣为原料,用酸提法制备氧化铝,采用单因素考察法确定了抚顺东露天油页岩残渣提取氧化铝的酸溶反应最佳工艺条件为:煅烧温度850℃,煅烧时间1h,所需原料粒度0.074mm,盐酸浓度为12%,液固比为5∶1,酸溶反应温度100℃,反应时间1.5h,各项工艺指标在最佳工艺条件下,Al2O3浸出率为81.75%;采用均相化学沉淀法由酸溶反应得到的氯化铝滤液制备氧化铝的最佳工艺条件为:反应温度55℃,偏铝酸钠浓度0.4mol/L,乙酸乙酯与铝离子物质的量之比为1.7∶1,反应时间1.5h,表面活性剂的用量为总体系质量的0.3%。采用激光粒度分布仪、X射线衍射仪、X射线荧光光谱仪对所制得的产物氧化铝进行了表征和分析研究。     

磁化处理技术在矿物加工中的应用

近年来,广大选矿、冶金科技工作者对磁化处理技术在矿物加工领域的应用进行了大量研究.文中重点介绍了磁化处理技术在矿物浮选、化学浸出、固液分离等过程中的应用研究及相关机理.     

氰化物添加系统的改造及效果

某矿山氰化厂对金精矿氰化浸出加氰化物系统进行自动化改造后,实现了浸出过程中氰化物的添加均衡稳定,氰化物浓度控制在要求值,优化了金氰化浸出指标,降低了氰化物消耗,实现了氰化物无泄露输送,安全环保.