硝酸浸出液中铝高效脱除的研究

本文以红土镍矿硝酸浸出液为对象,系统研究了硝酸浸出液中沉淀除铝环节,并提出一种高效沉淀除铝的新方法。详细考察了反应温度、陈化前pH值和陈化时间对沉淀除铝的影响,得到最佳工艺条件：反应温度为40℃、陈化前pH值为4.0~4.2和陈化时间为30 min。和常规沉淀法对比得出：最佳工艺条件下得到的铝渣镍、钴夹带率均小于1%,比常规沉淀法低3%以上；得到的沉淀矿浆固液分离容易,在负压0.04Mpa时,抽滤速度为0.22 m₃/(h.m₂),是常规沉淀法的12~13倍。本文成功解决了湿法冶金中铝沉淀后难过滤以及有价金属夹带多的难题,具有广阔的应用前景。

Study on High-efficiency Removal of Aluminum from Nitric Acid Leaching Liquor

In this article, the removal of aluminum from nitric acid leaching liquor of laterite was investigated, and a high-efficiency precipitation method of aluminum removal was presented. Effects of reaction temperature, pH value before aging and aging duration were examined in details. The optimum processing conditions were determined to be: reaction temperature being 40 °C, pH value before aging being 4.0~4.2 and aging time being 30 min. Comparing with the normal precipitation method, the entrainment rate of nickel and cobalt was <1% in the obtained aluminum precipitate slag, 3% less than the entrainment rate by the normal method; the filtration rate of aluminum precipitate slurry was faster than the normal method, when the filtration press being -0.04MPa, the former was 0.22 m₃/(h.m₂), 12~13 times faster than the latter, under the above optimum conditions. In a word, this high-efficiency precipitation method will be widely used in aluminum removal during hydrometallurgical process, due to its successful in solving the problems, such as the low filtration rate of aluminum precipitate slurry and high entrainment rate of valuable metals.