Abstract

Acid methods for processing of bauxites and aluminosilicates with high silicon content become attractive in connection with the exhaustion of natural alumina-containing resources suitable for processing by standard procedures based on using alkalis. The main problems in using acid procedures are associated with organization of closed-loop processes with low consumption of chemicals and power. The acid–salt technologies suggested by now are based on using ammonium hydrosulfate in the whole cycle and are economically inferior to the classical Bayer alkaline procedure. This study demonstrates on the laboratory level good prospects for developing a new efficient technology for alumina production from low-grade raw materials in a closed-loop process with recuperation of the consumed salt reagent in each cycle. The process takes advantage of the relationships of the aluminum and iron distribution in the solid phases and equilibrium solutions, revealed by the authors. Another feature is the use of a special method of acid retardation in nanoporous media for separating the residual amounts of the acid and salt, which are returned to the head of the process, with substantial saving of the power and chemicals.

中文翻译：

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闭环工艺中含氧化铝原料的酸盐处理的可行性

摘要

酸处理具有高硅含量的铝土矿和铝硅酸盐的方法与用尽适合使用基于碱的标准程序进行处理的天然含氧化铝资源有关，变得有吸引力。使用酸法的主要问题与低化学药品和电力消耗的闭环过程的组织有关。目前建议的酸盐技术是基于在整个循环中使用硫酸氢铵，并且在经济上不如传统的拜耳碱法。这项研究在实验室水平上展示了开发一种新的高效技术的良好前景，该技术将通过闭环工艺从低品位原料生产氧化铝，并在每个循环中回收消耗的盐试剂。作者揭示了该过程利用了固相中铝和铁分布与平衡溶液之间的关系。另一个特点是在纳米孔介质中使用了一种特殊的缓酸方法来分离残留的酸和盐，这些残留的酸和盐返回到过程的顶部，同时大大节省了功率和化学药品。