用氢氧化铝处理浮选循环水同时脱除钙离子和硫酸根离子

由于环境政策和经济因素,复杂硫化物矿的一些浮选作业用水循环使用,导致某些离子的浓度逐渐升高,影响到相关矿物的浮选。在此背景下,对含有高浓度钙和硫酸盐离子的合成溶液的处理进行实验研究和热力学分析。重点评估两种铝化合物对于Ca^(2+)和SO_(4)^(2-)以钙矾石形式析出过程的作用。结果发现,非晶态氢氧化铝比晶态氢氧化铝更为有效,可脱除高达83%的钙和91%的硫酸盐。对所得固体样品的XRD分析表明,因为吸收了大气中的二氧化碳,主要反应产物为钙矾石,伴随着少量的方解石。化学处理后的最终溶液中残留钙和硫酸盐的浓度低于200 mg/L。动力学研究发现,钙脱除过程对于钙浓度为二级反应,表观活化能为53.48 kJ/mol,表明钙矾石析出过程可能受化学反应控制。

复合硫化物浮选作业循环水中钙和硫酸根离子去除的热力学及实验研究

研究一种用氯化钡(BaCl_(2)∙2H_(2)O)和磷酸钠(Na_(3)PO_(4))去除饱和溶液中(0.016 mol/L CaSO_(4))硫酸钙的化学方法。主要目的是通过沉淀出两种固体物质从溶液中去除这些离子:硫酸根(SO_(4)^(2−))沉淀为重晶石(BaSO_(4)),钙(Ca^(2+))沉淀为羟基磷灰石(Ca_(5)(PO_(4))_(3)OH)。此外,探索一种用油酸和十二烷基胺作捕集剂的固体/液体分离方法(即浮选)。结果表明,在60℃、pH 11.5下用3.9 g/L BaCl_(2)·2H_(2)O和1.6 g/L Na_(3)PO_(4)对饱和溶液进行化学处理,促进硫酸钡和缺钙羟基磷灰石(Ca_(10−x)(HPO_(4))_(x)(PO_(4))_(6−x)(OH)_(2−x))的沉淀,钙和硫酸根的残余浓度分别低于0.10和5 mg/L。当反应剂用量相同、在低于上述温度和pH值下处理时,残余钙浓度增加到28 mg/L。用油酸作捕集剂、pH 9.5时羟基磷灰石的浮选回收率最高,约为80%;而用十二烷基胺作捕集剂、pH 6.5时重晶石的浮选回收率约为90%。

Effect of Temperature and the Organic Phase Content on the Stripping of Mn(II) from a D2EPHA-KEROSENE Pseudo-Emulsion Using a Sulfuric Acid Aqueous Solution

There are few studies oriented to analyze the interaction between the variables of the stripping process of actual leaching solutions. The aim of this work was to study the effect of temperature and the percent of organic phase in the stripping pseudo-emulsion (D2EPHA and kerosene) on the manganese stripping process. Other studied variables were the acid concentration (H2SO4) in the aqueous phase, the percent of the organic phase in the pseudo-emulsion and the number of stripping stages. This information may be of interest to countries with radical temperature variations. It was discovered that in the range of 10?C to 50?C, temperature improves the depletion of manganese from the D2EPHA. Additionally, the percent of the organic phase should be less than 90% by volume of the pseudo-emulsion to favour the manganese exchange. Moreover, the H2SO4 concentration in the aqueous phase should be less than 1 M to avoid chemical instability of the organic phase.