Optimization of gold recovery concentrates processing by the use of arsenatizing roasting, А.Y. Senchenko, А.V. Aksenov, and S.G. Rybkin
- Organization:
- The Southern African Institute of Mining and Metallurgy
- Pages:
- 10
- File Size:
- 1195 KB
- Publication Date:
- Jan 1, 2020
Abstract
For gold plants in Russia, it is very complicated and costly to use cyanide leaching for efficient
processing of gold refractory ores, where gold is closely associated with sulphide minerals and the
significant amount of natural carbonaceous matter present. Oxidative roasting of gold refractory
concentrates is a well-known method, making it possible to obtain a high recovery rate of precious
metals to a target product. The use of oxidative roasting is limited in general by the expense of capturing
and neutralising the harmful components of roasted gas, mainly sulphur (SO2, SO3) and arsenic (As2O3)
oxides. This paper addresses testing and development of an optimised technology to process gold
refractory gravity and flotation concentrates by means of oxidative roasting which stabilises arsenic as
calcium arsenate.
The process involves roasting of a gravity or flotation refractory ore concentrate in a mixture with
lime and calcium chloride, with a supply of oxygen, and at 600-700°С. During the roasting a
carbonaceous matter of the concentrate burns out and sulphide components transform into harmless
calcium sulphate (CaSO4) and calcium arsenate (Ca3(AsO4)2), and iron passes into the form of hematite
(Fe2O3). After disintegration, the roasting cinder is concentrated on a table to obtain a high-grade gravity
concentrate and gravity tailings. The high-grade gravity concentrate is subject to smelting in a mixture
with fluxing agents, which results in alloyed gold and slag. The gravity tailings are ground and reported
to cyanide leaching. In the case of a flotation concentrate, the roast cinder is ground to minus 30 μm and
subject to sorption cyanide leaching.
High gold recovery (90-95%) of the target product and environmental safety are typical of the
improved technology under consideration. Two national patents were granted for the methods developed
to treat refractory concentrates bearing precious metals.
Keywords: Gold concentrates, oxidative roasting, cinder, cyanide leaching, smelting, alloyed gold
Citation
APA: (2020) Optimization of gold recovery concentrates processing by the use of arsenatizing roasting, А.Y. Senchenko, А.V. Aksenov, and S.G. Rybkin
MLA: Optimization of gold recovery concentrates processing by the use of arsenatizing roasting, А.Y. Senchenko, А.V. Aksenov, and S.G. Rybkin. The Southern African Institute of Mining and Metallurgy, 2020.