METHOD AND ARRANGEMENT FOR PROCESS WATER TREATMENT

• Main Author: JANSSON, Kaj
• Format: Patent
• Language: English; French; German
• Published: 08.11.2023
• Subjects: CHEMISTRY; DIFFERENTIAL SEDIMENTATION; FERROUS OR NON-FERROUS ALLOYS; FLOTATION; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLIDMATERIALS OR FLUIDS; METALLURGY; PERFORMING OPERATIONS; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATICTABLES OR JIGS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS; SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATICTABLES OR JIGS; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

A method of treating process water of a flotation plant is disclosed. The flotation plant comprises a mineral flotation line and a process water circuit for treating underflow and/or overflow of the flotation line. The process water circuit comprises a gravitational solid-liquid separator for dewatering underflow and/or overflow of the mineral flotation line to separate sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; and a recover water tank for collecting process water. According to the method, prior to leading supernatant from the gravitational solid-liquid separator into the recover water tank, it is subjected to cleaning flotation, in which at least 90% of the flotation gas bubbles have a size from 0.2 to 250 μm, in a cleaning flotation unit. An arrangement for treating process water of a flotation plant, and its use are also disclosed.