Pyrite concentrates with refractory gold and silver were roasted at different temperatures to improve the recovery of metals by cyanide leaching. Scanning Electron Microscope characterization calcine revealed that occluded in pyrite less than one micron, roasting produced channels concentrate, exposing particles leaching solution. Gold recoveries maximum temperature range 500-600?C due high sur...

This review describes the historical development and current state of metals leaching and sulfide mineral biooxidation by the minerals industries. During the past 20 years commercial processes employing microorganisms for mineral recovery have progressed from rather uncontrolled copper dump leaching to mineral oxidation and leaching in designed bioheaps for oxidation of refractory gold ores and...

 Cyanidation is a relatively simple and cheap technology to treat gold-containing ores. However, this process is not completely effective in refractory gold-bearing sulfide ores. In the case of very low-grade ores, biooxidation is an attractive alternative pre-treatment to render the gold amenable to extraction. This process utilizes the ability of acidophilic bacteria to oxidize the sulfide m...

BACKGROUND Although clozapine is the 'gold standard' for treatment-refractory schizophrenia, meta-analyses of clozapine for this condition are lacking. AIMS We conducted a systematic review and meta-analysis of clozapine treatment for people with treatment-refractory schizophrenia. METHOD We searched the Cochrane Schizophrenia Group's trial register, PubMed and EMBASE and hand-searched key ...

Among the methods of preliminary opening refractory gold before sorption cyanidation, technology bacterial oxidation is widely used today. Although this has many advantages, specialists most enterprises around world using are faced with problem foaming in bio-oxidation reactors. This article discusses possibility oxidative roasting processing foam product process flotation concentrate a separat...