Technology Development of Gold Heap Leaching in Kazakhstan: An Overview

Kazakhstan has exhibited consistent growth in gold production and is currently ranked among the top ten leading countries in the field. This article provides an overview of the development of heap leaching technology for extracting gold from oxidized ores in Kazakhstan. Key factors influencing the efficiency of the heap leaching process are discussed, including the mineralogical composition of the ores, the particle size of the gold, the presence of associated minerals, and the challenges posed by leaching in harsh climatic conditions. The main characteristics of Kazakhstan’s heap leaching plants are presented. A comparative analysis is conducted with global practices, including those in the USA, Canada, China, Russia, Uzbekistan, and other countries. This analysis covers the main stages of the process: ore preparation, gold recovery from pregnant solutions through cementation, adsorption onto activated carbon and ion-exchange resins, desorption, and sorbent regeneration. The advantages and disadvantages of different methods for extracting gold from solutions are identified, along with an evaluation of the costs associated with sorbents. Special attention is given to the Kazmekhanobr developed technology for the intensive regeneration of ion-exchange resins saturated with gold. Additionally, capital and operational costs associated with the heap leaching process are examined, alongside environmental considerations.