酸法制粒堆浸研究的现状、原理与实践

对于含泥低渗透性酸性矿石,搅拌浸出或常规堆浸工艺均难以获得理想的浸出效果及经济指标,采用酸法制粒堆浸是目前最有效的处理办法。对酸法制粒堆浸的国内外研究现状、研究的基本原理等进行了探讨,并对该技术在中国进行的首次工业应用情况进行了简单介绍。

金川低品位氧化镍矿的酸法制粒堆浸工艺研究

对于金川有色金属公司低品位的氧化镍矿,目前的火法和湿法冶金工艺,生产成本高,难以回收利用。通过制粒预处理,加入润湿液与矿石中的耗酸组分作用,可以预先破坏碳酸盐和Ca、Mg的氧化物,降低硫酸浸出过程中CO2气体逸出对颗粒的损害。选择N603作为低品位氧化镍矿的黏合剂,有效地改善了堆浸的渗透性,浸出过程中,矿石颗粒未发现严重的破裂和泥化现象。预处理后矿石浸出,每t矿石总用酸量258.8kg,镍浸出率85%以上。如果利用该公司硫酸厂大量的低浓度硫酸来堆浸,则在经济上和环境保护方面都比较合理。

高岭土胶结型铀矿的酸法制粒堆浸研究

对于高岭土胶结型铀矿,由于矿石渗透性太差而无法采用常规的堆浸工艺处理.但对矿石进行酸法制粒预处理后和串联堆浸工艺后,矿石的渗透性能可达到500L/m2.h以上,浸出的合格液平均铀浓度大于5g/L,矿石的铀金属浸出率超过95%,渣品位低于0.02%.而酸耗仅为3.33%.

某氧化锌矿酸法制粒浸出探索试验

本文是对经过破碎后的某氧化锌矿采用自制的粘合剂进行制粒条件试验研究。选择最佳的制粒条件,粘合剂用量为3%,润湿剂水用量为12%,对制好的粒球进行柱浸试验,通过22天浸出,液计浸出率为19.67%,渣计浸出率为15.79%,塌实度为18.2%。

地表氧化铜矿酸法制粒堆浸试验研究

地表氧化铜矿采用浮选、冶炼方法等一般无法回收,采用搅拌浸出由于品位低,不一定有好的经济效益,因而选用成本低的造粒堆浸,针对高含泥质矿石的渗透性问题,试验成功找到一种价廉易得耐酸的LN3粘合剂,用它造粒后,矿石渗透性大大提高,能满足堆浸要求,浸出率大于95%,浸出酸耗为93 kg/t的矿石。

某含钴、铜尾矿的浸出研究

对某低品位、细粒度的含钴、铜尾矿进行了浸出研究。研究了原矿渗透性、粒级分布、浸出温度及还原剂用量对浸出的影响。对价廉的矿物性粘合剂LN1、LN2、LN3、LN4进行了比对选择和互配试验,最终采用价廉、实用、耐酸的LN1与LN3作粘合剂,并对它们进行了互配柱浸试验,Cu、Co浸出达到了满意的结果,为堆浸综合回收尾矿中的Cu、Co提供了一种可供选择的方案。

Comparative study on photocatalytic properties of TiO_2 nanoparticles prepared in acidic medium and basic medium by hydrothermal method

In order to investigate the difference of phtotocatalytic properties of TiO2 samples prepared in different pH conditions, TiO2 nanopartieles were prepared in acidic medium and basic medium by a hydrothermal process, respectively. The samples were characterized using XRD, TEM, BET, XPS, surface photovoltage spectroscopy （SPS） and field-induced surface photovohage spectroscopy （FISPS）. Effects of temperature and pH in the hydrothermal process on particle sizes, specific surface areas, and photoeatalytic properties of the TiO2 nanoerystalline were investigated. The experimental results indicate that the photocatalysis activity of TiO2 nanoparticles prepared in basic medium （ B-TiO2 ） is superior to that in acidic medium （ A-TiO2 ）, which is ascribed to the difference of surface state between A-TiO2 and B-TiO2.

Process optimization for the enhanced stability of diclofenac potassium granules and capsules

This study aimed to investigate the effects of different process parameters on the physical properties, in vitro dissolution rate, and short and long-term stability of diclofenac potassium（DFP） granules and capsules. DFP granules exhibited low total amounts of impurities when prepared through the wet granulation method using a granulating solvent with a low water/ethanol ratio. The impurities of the wet DFP mass dried at 70 ℃ were higher than those dried at 50 ℃ or 60 ℃. DFP granules were stable under strong light exposure during preparation. DFP granules prepared using a granulating solvent with a 1：4 water/ethanol ratio had a relatively smaller particle size and higher angle of repose than those prepared using granulating solvents with other water/ethanol ratios. The dissolution rate of DFP capsules prepared using four different water/ethanol ratios was less than 2% after 10 min of dissolution and increased to 95% within 30 min of dissolution. The total amount of drug impurities of DFP capsules prepared using a granulating solvent with 1：4 water/ethanol ratio was considerably lower than those of DFP capsules prepared using a granulating solvent with a 1：0 water/ethanol solvent ratio. Regardless of the water/ethanol ratio, the capsules showed poor stability when exposed to high temperature（60 ℃） and strong light（4500±500 Lux） for 10 days, but were relatively stable at high humidity（92.5% RH）. The results of the long-term stability（25±2 ℃ and 60%±10% relative humidity） study showed that DFP granules were more stable than DFP capsules, and were stable for 12 months. The type of encapsulating material did not affect the 2-month stability of DFP. DFP granules are sensitive to granulating solvent and drying temperature and DFP capsules should be stored away from high temperature and strong light.