Recovery of Zn, Pb, Fe and Si from a low-grade mining ore by sulfidation roasting-beneficiation-leaching processes

To recover Zn, Pb, Fe and Si from a low-grade mining ore in the Lanping basin, Yunnan Province, China, a novel technology using the roasting with pyrite and carbon followed by beneficiation and hydrochloric acid leaching was proposed. Firstly, several factors such as pyrite dosage, roasting temperature, carbon powder dosage, holding time and particle size affecting on the flotation performance of Zn(Pb) and magnetic separation performance of Fe were simultaneously examined and the optimum process parameters were determined. A flotation concentrate, containing 17.46% Zn and 3.93% Pb, was obtained, and the Zn and Pb recoveries were 86.04% and 69.08%, respectively. The obtained flotation tailing was concentrated by a low-intensity magnetic separator. The grade of iron increased from 5.45% to 43.45% and the recovery of iron reached 64.87%. Hydrochloric acid leaching was then carried out for the magnetic separation tailing and a raw quartz concentrate containing 81.05% SiO2 was obtained. To further interpret the sulfidation mechanism of smithsonite, surface morphology and component of the sample before and after reactions were characterized by XRD and EPMA-EDS. The aim was to achieve the comprehensive utilization of the low-grade mining ore.

Upgrading and dephosphorization of Western Australian iron ore using reduction roasting by adding sodium carbonate

The technology of direct reduction by adding sodium carbonate （Na2CO3） and magnetic separation was developed to treat Western Australian high phosphorus iron ore. The iron ore and reduced product were investigated by optical microscopy and scanning electron microscopy. It is found that phosphorus exists within limonite in the form of solid solution, which cannot be removed through traditional ways. During reduction roasting, Na2CO3 reacts with gangue minerals （SiO2 and A1203）, forming aluminum silicate-containing phosphorus and damaging the ore structure, which promotes the separation between iron and phosphorus during magnetic separation. Meanwhile, Na2CO3 also improves the growth of iron grains, increasing the iron grade and iron recovery. The iron concentrate, assaying 94.12wt% Fe and 0.07wt% P at the iron recovery of 96.83% and the dephosphorization rate of 74.08%, is obtained under the optimum conditions. The final product （metal iron powder） after briquetting can be used as the burden for steelmaking by an alactrie a.re furnace to rer）la,ce scrar） steel.

低品位金钼混合精矿提取金钼新工艺

采用氧化焙烧脱硫、除碳-碳酸钠溶液浸出钼-浸钼渣氰化提金新工艺处理某金钼混合精矿。结果表明，在下述最佳试验条件下：粗精矿于600℃氧化焙烧1．5h、钼焙砂加入矿重40％的碳酸钠后按液固比3～4在80～90℃浸出1．0～1．5h，钼浸出率为91％，浸钼渣金的氰化浸出率大于95％。

轻烧高铝矾土碳化法制氢氧化铝工艺研究

该法简述了铝、钙氧化物低碱化复合焙烧、碳化法制取氢氧化铝及副产Ｎａ２ＣＯ３回收应用的新工艺。

Na_4Ca_3(AlO_2)_(10)的合成和浸出行为

以分析纯CaCO3,Al2O3和Na2CO3为原料,在1100～1250℃合成了Na4Ca3（AlO2）10,研究了浸出时间、浸出温度、液固比及溶液中碳酸钠和氢氧化钠浓度对Na4Ca3（AlO2）10浸出性能的影响.结果表明,在1200℃烧结30 min,可以合成纯度高于90%的Na4Ca3（AlO2）10.当碳酸钠浓度为80 g/L、氢氧化钠浓度18 g/L时,Na4Ca3（AlO2）10在40℃浸出10 min的氧化铝浸出率达到90%以上.当碳酸钠浓度降为30 g/L时,Na4Ca3（AlO2）10在60℃浸出15 min的氧化铝浸出率大于85%.浸出时添加氢氧化钠有利于氧化铝浸出率的提高,氢氧化钠浓度大于5 g/L时,氧化铝浸出率可提高10%以上.Na4Ca3（AlO2）10的浸出性能优于12CaO·Al2O3和CaO·Al2O3.

废SCR脱硝催化剂钒、钛、钨选择性分离研究

分别采用NaOH、HCl浸出废SCR催化剂,碳酸钠焙烧-水浸废SCR催化剂选择性分离钛。试验表明:碳酸钠焙烧-水浸废催化剂可实现钛与钒、钨高效分离。较优工艺条件:焙烧温度850℃,焙烧时间3 h,碳酸钠与废催化剂质量比为1.3,浸出温度95℃,浸出时间1 h,搅拌速度500 r/min。V、As、W的浸出率分别为52.26%,98.24%和99.9%。采用硫酸浸出废SCR催化剂钠化焙烧渣实现高效提取钛。工艺条件:上述较优条件焙烧渣,40%硫酸,液固比4∶1,浸出温度90℃,浸出时间3 h,搅拌速度500 r/min。钛的浸出率为93.4%。采用自生晶种水解法制备偏钛酸,钛水解率为94.05%,偏钛酸纯度为94.07%。