Shayakhmetova R A, Mukhametzhanova A A, Akbayeva D N, Terlikbaeva A Zh, Osipov P A, Alimzhanova A M, Zharmenov A A
Republican State Enterprise National Center for Complex Processing of Mineral Raw Materials of the Republic of Kazakhstan, RSE "NC CPMRM RK", Zhandosov st., 67, Almaty, 050036, Kazakhstan.
al-Farabi Kazakh National University, al-Farabi ave., 71, Almaty, 050040, Kazakhstan.
Sci Rep. 2024 Dec 30;14(1):31866. doi: 10.1038/s41598-024-83239-0.
Waste generated during asbestos manufacturing contains substantial quantities of iron, nickel, magnesium, and silicon. The existing techniques for processing chrysotile-asbestos waste (CAW) cannot fully recover these elements. Therefore this paper presents a hydrometallurgical method for processing the CAW of the Zhitikara deposit in the Kostanay region of Kazakhstan. Batch reactors are used in both laboratory and pilot experiments, and initial trials are conducted in a recently constructed industrial Ti reactor at the Kostanay Minerals JSC plant in the Kostanay region of Zhitikara. The primary benefits of the industrial reactor include operation without excessively grinding the feedstock and creation of a pulp with enhanced filtration properties. A moderate agitation speed (10 rpm) helps ensure a consistent pulp density and prevent the production of silica gel. Optimal leaching conditions are determined as a fraction size of CAW between - 1.25 and 0.25 mm, hydrochloric acid concentration of 18 wt%, temperature of ~ 85-90 °C, pressure of 1 atmosphere, and duration of 2 h. An investigation of the process kinetics reveals that diffusion is the rate-controlling step. Further, the activation energies are determined to be 54.4 kJ.mol, and the leaching rates of Mg, Fe, and Ni under these conditions are 96.0, 87.8, and 81.3%, respectively. Washing and recycling water enhances helps to increase the recovery of magnesium chloride. Implementing pilot-scale hydrometallurgical processing of CAW can effectively address environmental issues that pose a threat to human health and provide commercial advantages.
石棉制造过程中产生的废物含有大量的铁、镍、镁和硅。现有的温石棉废物（CAW）处理技术无法完全回收这些元素。因此，本文提出了一种湿法冶金方法来处理哈萨克斯坦科斯塔奈地区日季卡拉矿床的CAW。实验室和中试实验均使用间歇式反应器，初步试验在日季卡拉科斯塔奈地区科斯塔奈矿物股份公司工厂新建成的工业钛反应器中进行。该工业反应器的主要优点包括无需对原料进行过度研磨即可运行，以及能够制备具有增强过滤性能的矿浆。适中的搅拌速度（10转/分钟）有助于确保矿浆密度一致，并防止硅胶的产生。确定的最佳浸出条件为：CAW的粒度在-1.25至0.25毫米之间，盐酸浓度为18重量%，温度约为85-90°C，压力为1个大气压，持续时间为2小时。对该过程动力学的研究表明，扩散是速率控制步骤。此外，确定活化能为54.4千焦/摩尔，在这些条件下镁、铁和镍的浸出率分别为96.0%、87.8%和81.3%。洗涤和循环用水有助于提高氯化镁的回收率。实施CAW的中试规模湿法冶金处理可以有效解决对人类健康构成威胁的环境问题，并提供商业优势。
