Gold Hydro-metallurgy

Suntech develops and tests hydrometallurgical flow sheets for the recovery of gold from ores, concentrates and tailings using conventional and intensive cyanidation as the principal processes. The laboratory has acquired skills in establishing accurately the leachability of gold from ores of different mineralogical make evaluating the effectiveness of different circuits including CIP (Carbon in pulp), CIL (Carbon in leach) and CIS (Carbon in solution) configurations. The laboratory uses different techniques to effect leaching with bottle rolling and mechanical agitation being the most favourable while VAT and Heap leaching are only considered for ores with considerably low gold concentrations or when absolutely necessary.

The laboratory is also setup to generate and properly store leach liquors for comprehensive ICP analyses and for cyanide speciation tests. Alongside these tests, we are also able to determine total sulphur, ANC, NAG, TAPP, NAPP, NAG pH and NAG conductivity for completion of Acid mine drainage studies. Whilst set up to carry out conventional testing, Suntech is wide open to exploring new areas researching jointly with clients to develop innovative solutions, updating and developing process options.

Gold recovery process test works

With oxidized free-milling gold reserves fast running out, gold miners have resorted to exploitation of refractory gold ore bodies; Suntech has responded by sharpening skills for developing solutions for successful recovery of the gold from the ever increasing refractoriness of the ores. Suntech continues to search for new recovery methods as the complexity of upgrading processes like gravity concentration, DMS, flotation, etc., persists. The gold leach chemistry is also becoming a progressively more complicated compromise between maximizing gold recovery and suppressing leaching of undesirable ore constituents.

Furthermore, projects such as reclamation of low gold grade tailings (containing residual precipitated cyanide, mercury and other process residues in high concentrations) or poly-metal ore bodies can be faced with problems relating to gold deportment and assaying before even considering processing options.
Pro-active engineering and design for gold projects could be challenging with regards to compliance with discharge criteria and closing of water and energy balances, which are to be linked to both national and international regulations.

SUNTECH’s gold processing group specialise in process flow sheet development for new or existing gold deposits with a recent focus on refractory and low grade reclamation projects.

Metallurgical expertise and capabilities

We have all of the expertise and equipment necessary to complete the requisite test work leading to development of flotation flowsheets coupled with leaching. To date, Suntech has completed a handful of tests at both bench and pilot plant scales. Supported by our internal accredited analytical services department, the metallurgical division of Suntech has successfully completed a number of studies at Bankable feasibility levels in gold and PGM testing. This coupled with our un-paralleled expertise in metallurgical testing capabilities and reputation makes us your preferred one stop shop.

Rare earths elements

Over the years, Suntech has developed methods for recovery and upgrading rare earths elements by flotation. The laboratory is also involved in projects which involve stage–leaching and precipitation to remove the impurities from the rare earth containing process stream and thereby obtaining a concentrated stream suitable for further purification.


Core Expertise

  • Cyanidation
  • Leaching
  • Precipitation
  • Cementation

Contact For Services

SA Region

+27 (0)11 433 4234

+27 (0)76 102 4182

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