Method of processing and treatment of alunite ores

Process for the treatment of alunite ore with sodium carbonate Na2CO3, comprising the following steps:

• crushing of alunite ore,
• grinding the alunite ore,
• enrichment of the grinded alunite ore by flotation to the content of at least 50% of the alunite ore by weight,
• roasting the enriched alunite ore at 520 to 620° C. for 1 to 3 hours,
• preparing a sodium carbonate solution comprising 5 to 20% sodium carbonate by weight, which is later used in a first leaching step, wherein the sodium carbonate solution is added to the roasted alunite ore in a quantity of 100 to 110% of the stoichiometric amount required to bond to sulphate ions from aluminum sulfate in the roasted alunite ore, thereby forming a sodium sulphate solution wherein sodium sulphate is present at a 0 to 10% excess over the stoichiometric balance of the equation,
• K2SO4+Al2(SO4)3+2Al2O3+waste rock+3Na2CO3=K2SO4+3Na2SO4+3Al2O3+waste rock+3CO2,
• separating the sodium sulphate solution from an insoluble residue of the first leaching step,
• converting the sodium sulphate in the preparing step with KCl to potassium sulphate and sodium chloride to form a suspension,
• filtering and washing the suspension with water to form a filtrate,
• evaporating the filtrate and the water, and
• a second leaching step comprising treating the insoluble residue by the Bayer method without the use of an autoclave to form a product comprising aluminium oxide and quartz sand to produce aluminium oxide, potassium sulphate, quartz sand, coagulant for the purification of utility and potable water, and kitchen salt.

Process for the treatment of alunite ore comprising the following steps:

• A. crushing said alunite ore,
• B. grinding said crushed alunite ore,
• C. enriching said ground alunite ore by flotation to the content of at least 50% of alunite by weight,
• D. roasting said enriched alunite ore at 520 to 620° C. for 1 to 3 hours,
• E. preparing a sodium salt solution that comprises 5 to 20% sodium carbonate (Na2CO3) by weight,
• F. combining said sodium salt solution and said roasted alunite ore, wherein said sodium salt solution is present in 100 to 110% of the stoichiometric amount required to bond to the sulfate ions from aluminum sulfate that is present in said roasted alunite ore, thereby forming a slurry, further wherein said slurry comprises a liquid component and an insoluble residue, further wherein said liquid component comprises potassium sulphate and sodium sulphate, and further wherein said insoluble residue comprises aluminum oxide,
• G. separating said liquid component from said insoluble residue,
• H. treating said liquid component with KCl to form potassium sulphate and sodium chloride,
• I. treating said insoluble residue by the Bayer method without the use of an autoclave to form aluminium oxide and quartz sand.