Process Water Treatment (Mining)

Mine water treatment chemicals are the coagulants, flocculants, pHnadjusters, and scale inhibitors used to clarify, neutralize, and recycle thenprocess water moving through grinding, flotation, leaching, and tailingsncircuits. A working program almost always combines two functions:nraising pH to precipitate dissolved metals, then settling the resulting solids.nSpecify the pH stage and the clarification stage separately, because the reagentnthat neutralizes acidity is rarely the one that drops the floc.

Lime and caustic soda are the two standard alkalis. Calcium oxide (quicklime)nis the lower cost-per-tonne option and the workhorse for neutralizing acidicndrainage, but it adds slaking, handling, and extra settled solids. Caustic sodanmeters cleanly as a liquid and gives tighter pH control at a higher reagent cost.nWhere solids loading is already high, the cleaner dosing of caustic can pay backnthrough smaller thickeners; where reagent cost rules, lime wins.

Clarification relies on a coagulant plus a flocculant. Ferric chloride andnaluminium sulfate neutralize the charge on fine suspended solids; anhigh-molecular-weight polyacrylamide or a cationic polyDADMAC then bridges thendestabilized particles into settleable flocs. Run a jar test before fixing dose:nunderflow density and overflow clarity both shift sharply with thencoagulant-to-flocculant ratio, and overdosing the polymer can re-stabilize thenvery solids you are trying to drop.

• Neutralizing acidic mine drainage and metal-laden process water before discharge or reuse
• Coagulation and flocculation in thickeners to raise underflow density and clarify overflow
• Tailings dewatering and process-water recovery for recycle
• Settling-pond and clarifier solids control across grinding and flotation circuits
• pH conditioning of heap- and tank-leach process water

• Calcium oxide u2014 PubChem
• Sodium hydroxide u2014 PubChem
• Ferric chloride u2014 PubChem
• Aluminium sulfate u2014 PubChem
• Polyacrylamide u2014 PubChem