GOLD EXTRACTION associated with cyanide transportation and potential spill events. No toxic gases or acids are emitted.
Laboratory test work and engineering investigations have shown that some 10 samples of refractory gold-bearing materials all responded well to KellGold and poorly to cyanidation, suggesting that the cyanide-free KellGold process could potentially unlock the value from conventional refractory concentrates, double refractory carbonaceous concentrates, calcine tailings dumps and copper-gold concentrates, inclusive of highly arsenical and antimonial cases. The process could potentially provide an alternative to concentrate treatment at a copper smelter, avoiding transport, treatment and refining charges as well as comparatively low Net Smelter Return( NSR) payments( 70-80 % of metal value).
Mike Adams, Process Consultant( Kell Process) and author of the new Elsevier book Gold Ore Processing: Project Development and Operations, 2nd Edition says“ the high metal recoveries, along with the elimination of both cyanide usage and toxic gaseous emissions, warrants the serious consideration of the KellGold process in any refractory gold, coppergold or polymetallic project or operation. The process may represent the next step change towards clean processing of refractory and polymetallic gold concentrates.”
Gold and water
Water plays a key role in many of the processes to recover gold. It is also a valuable resource that must be used and re-used efficiently. Kemira’ s line of mining products combined with its application expertise can help. Kemira offers a broad range of chemistries that are widely used in the processing of all types of gold ores. Kemira says its“ expertise in water quality and quantity management enables us to add value to these water-intensive processes.”
One example of this is an extensive line of scale-control products. Scale build-up, for instance in the heap leach distribution system, is often an unseen problem that can block pipework and nozzles, causing significant decreases in productivity if they are not managed properly. Kemira ' s wide range of KemGuard ® chemistries can help prevent this scaling problem. The KemGuard 5000m series offers a unique polycarboxylate chemistry that is highly effective at controlling calcium sulphate and calcium carbonate under a wide range of pH conditions. These inhibitors include very effective dispersants and crystal nucleation retarders, proven effective in gold operations in high pH / cyanide conditions.
Proper solid-liquid separation is key to increased production rates, and here Kemira suggests Superfloc ® flocculants. It reports:“ Superfloc products have been effective in waterintensive gold mining applications for many years. Flocculants are commonly used in both flotation and leaching operations for pre- and post-leach thickening, counter current decantation( CCD), paste and tails thickening duties. Kemira offers a full range of anionic, nonionic, and cationic products to ensure the correct product charge both with and without lime addition. Additionally the Superfloc portfolio, featuring a wide range of molecular weights, is ideal for high-rate, ultra-high rate and paste thickeners. The high molecular weight cationic flocculants are ideally suited for Biox CCD circuits.”
Along with the Superfloc products, Kemira is a major manufacturer of both organic and inorganic coagulants. These are particularly relevant in gold-processing for waste water clarification as well as arsenic-, selenium- and heavy metalsremoval processes.
Kemira offers an even broader array of solutions to improve customers ' processes including defoamers to control foam in concentrate thickeners and BIOX leach tanks. In Europe and Africa, Kemira supplies hydrogen peroxide used to manage the oxidation potential within CIL / CIP circuits and for cyanide destruction circuits. Kemira is a major producer of H 2O 2 in Europe with plants in Finland, Sweden, and the Netherlands. The product can be supplied as 60 % or 70 % solution. IM
5
th Latin American Congress on Desalination and Water Reuse
October 5 ~ 7
Hotel Sheraton, Santiago, Chile
Special discounts for companies
Register on gecamin. com / desal
AREAS OF INTEREST
Design and construction of desalination plants • Operation and maintenance • Development of water projects in the public sector • Energy for desalination • Reuse of effluents and wastewater • Treatment of effluents • Environmental aspects of desalination • New desalination technologies • Marine works • Long distance and high altitude water transport systems
EXECUTIVE COMMITTEE
president of the organizing committee José Joaquín Muñoz Director, Seven Seas Water, Chile
technical coordinator Raymond Philippe Business Development Manager and Water Sector Lead, MWH Global, Chile
adjunct technical coordinator Andreína García Researcher, Advanced Mining Technology Center, Universidad de Chile
ORGANIZERS INSTITUTIONAL PARTNERS
MINNOVEX
P r o v e e d o r e s d e C l a s e M u n d i a l
AUGUST 2016 | International Mining 77