Patent DE-102009041143-A1 (DE)
Title: Processing mining waste water comprises separating sulfur metal ions and sulfate from water, reducing sulfur metal ions and sulfate to sulfide and removing the sulfide from waste water, and oxidizing the waste water loaded with iron salts
Inventor: OOSTHUIZEN FREDERICK SIMON
IPC: C02F1/70
Filed: 2009-09-14
Abstract: The method for processing mining waste water (1), comprises separating sulfur metal ions and sulfate from the water, reducing sulfur metal ions and sulfate to sulfide and removing the formed sulfide from the mining waste water, and oxidizing the mining waste water loaded with iron(II) salts in a heat exchanger device (7) in a cooling circuit of a steam turbine. The oxidization is carried out by adding air (6) and waste heat (5) and forwarding the process water in several ventilated partial streams at reduced flow rate through channels (2) provided with electrodes. The method for processing mining waste water (1), comprises separating sulfur metal ions and sulfate from the water, reducing sulfur metal ions and sulfate to sulfide and removing the formed sulfide from the mining waste water, and oxidizing the mining waste water loaded with iron(II) salts in a heat exchanger device (7) in a cooling circuit of a steam turbine. The oxidization is carried out by adding air (6) and waste heat (5) and forwarding the process water in several ventilated partial streams at reduced flow rate through channels (2) provided with electrodes, where the undissolved substances are electrochemically removed. The formed metal hydroxide after floatation in the channels is removed in a separating step, with a discharging device. The mining waste water to be treated is oxidized before the electrochemical process. Barium carbonate is directly added to the mining waste water, where barium sulfate, metal hydroxide and metal carbonate are separated. The pH of the process water is neutralized. The barium sulfate and metal hydroxide/metal carbonate is obtained from the residue of a cyclone filter device. The barium sulfate and metal hydroxide/metal carbonate are thermally treated at a temperature less than 1000[deg] C. The metal hydroxide obtained from the oxidation of the thermal process is supplied for disposal. The barium carbonate is supplied after the electrochemical separation of undissolved substances. The drying of residue is carried out over waste heat of the steam turbine and mixed with coal dust. The residue and the mixed coal dust are heated after the drying process before the mixture of process residue and coal dust is chemically converted in a furnace. The process heat formed in the interior of the furnace by the chemical process is removed. The residue and coal dust are chemically converted as powder mixture in a direct manner. The resulting substances such as barium sulfide, iron sulfide, ash and carbon dioxide are supplied into a closed collecting tank. The resulting gases such as hydrogen sulfide, carbon dioxide and water vapor are fed into a sulfur treatment plant. The resulting heat from the combustion of coal dust and the reaction-energy are stored as heat energy in a thermal oil storage tank. The brine from a reverse osmosis system is treated in a vacuum evaporator for separating the dissolved salts and undissolved substances, where the heat energy required for the heating and evaporating for the process is obtained from the waste heat of thermal utilization process of exothermal chemical reaction. The brine from a reverse osmosis system in an evaporation tank is treated with a tube bundle heat exchanger embossed at the bottom for separating the dissolved salts and undissolved substances, where the heat required for heating is obtained from the thermal process. The thermal energy from the combustion of coal dust and the chemical reaction energy from the powder mixture of a power generation facility are supplied. The generated energy is supplied to the process.