Boliden process

In the Boliden process, developed by Boliden Kemi Company in Sweden, filter beds containing amorphous selenium are used to filter the gases. Mercury in the gas is deposited in the filter as mercury selenide (HgSe). Alternatively, the gases can be scrubbed with a slurry of amorphous selenium, whereupon mercury is precipitated as HgSe. Activated carbon filters are also useful for absorbing mercury vapor from the gas. 

Sultrol A flue-gas desulfurization process, similar to the Flakt-Boliden process, but using potassium citrate instead of sodium citrate. Developed by Pfizer and announced in 1985, but not known to have been commercialized. 

Farrington, J. F. and S. Bengtsson, "The Flakt-Boliden Process for SO2 Recovery", presented at AIME annual Meeting, February 19, 1979. 

Flakt-Boliden process aqueous carbonate SULF-X process Conosox process... 

In the Odda process, used by Det Norske Zinkkompani in Norway in collaboration with Boliden Kemi, the gases are subjected to scrubbing with a mercuric chloride solution which reacts with mercury, yielding insoluble mercurous chloride this can be separated by filtering. 

Boliden (1) An obsolete process for reducing sulfur dioxide to elemental sulfur, using hot coke. Operated in Sweden by Boliden from 1933 to 1943. See also Trail, RESOX. 

Boliden (2) A lead extraction process in which a sulfide ore, mixed with coke, is smelted in an electric furnace, air jets forming vortices between the electrodes. Discontinued in 1988 in favor of the Kaldo process, using a rotating furnace. 

The precipitated mercurous chloride separates as a sludge. In the original process, some of this mercurous chloride was chlorinated to mercuric chloride for re-use. In a later version of the process, all the mercuric chloride is electrolytically converted to elemental mercury and chlorine. As of 1994 the electrolytic version had been installed in three plants. Developed by Boliden, Sweden, and Norzink, Norway, and now offered for license by Boliden Contech. 

Bolkem [Boliden] A process for removing mercury from the sulfuric acid from metallurgical smelters. Addition of aqueous sodium thiosulfate causes mercuric sulfide to be precipitated. Operated at Helsingborg, Sweden, since 1974. 

Flakt-Boliden A variation on the Citrate process for flue-gas desulfurization in which the sulfur dioxide is removed from the citrate solution by vacuum. Developed by Flakt, United States, and piloted in 1980 at the TVA Electric Power Research Institute, Muscle Shoals, AL. 

Carbonyl sulfide is an intermediate in this reaction. A mixture of sulfur dioxide and oxygen was blown into the bottom of coke-fired reduction furnace and sulfur vapor condensed from the off-gases. Trail is the location of a large mine and smelter in British Columbia. The process was originally used in the 1930s for abating air pollution from the smelter, but when the demand for sulfuric acid for fertilizer production increased in 1943 it became obsolete. See also Boliden (1), RESOX. 

Bois de rose, in perfumes, 1<5 366 Boliden s Kaldo lead smelting process,... 

Boliden s Kaldo process of, 14 742-743 Isasmelt process of, 14 743-745 Kivcet process of, 14 739-740 Outokumpu process of, 14 745 QSL process of, 14 740-742 Lead stabilizers, for PVC polymers, 25 671 Lead storage battery, 14 783. See also Lead-acid batteries Lead-calcium alloy batteries... 

These processes are referred to as the Boliden Norzink Mercury Removal Process (Boliden Norzink, 2004) and the selenium filter process (Selenium Filter, 2004). Combined sequentially, they keep Hg-in-sulfuric acid below 0.25 parts per million. 

An alternative is to pass Boliden Norzink exit gas through a column of activated PbS coated pumice (Dowa Process). This precipitates solid HgS and keeps Hg-in-sulfuric acid below 0.05 parts per million (Lossin and Windhager, 1999). 

Boliden Norzink (2004) The Boliden Norzink mercury removal process. Outokumpu Technology AB, Skelleftea, Sweden www.outokumpu.com... 

The Flakt-Boliden version of the citrate process uses thermal regeneration of the citrate absorbing solution to obtain stripped citrate solution and a stream of up to 90% sulfur dioxide. Recovery of a sulfur dioxide product gives flexibility to the final stage of processing as to whether liquid sulfur dioxide, sulfuric acid, or sulfur are obtained as the final product. This process has recently been reexamined [42]. 

Metallic arsenic can be obtained by the direct smelting of the minerals arsenopyrite or loellingite. The arsenic vapor is sublimed when these minerals are heated to about 650—700°C in the absence of air. The metal can also be prepared commercially by the reduction of arsenic trioxide with charcoal. The oxide and charcoal are mixed and placed into a horizontal steel retort jacketed with fire-brick which is then gas-fired. The reduced arsenic vapor is collected in a water-cooled condenser (5). In a process used by Boliden Aktiebolag (6), the steel retort, heated to 700—800°C in an electric furnace, is equipped with a demountable air-cooled condenser. The off-gases are cleaned in a scrubber system. The yield of metallic arsenic from the reduction of arsenic trioxide with carbon and carbon monoxide has been studied (7) and a process has been patented describing the gaseous reduction of arsenic trioxide to metal (8). 

Sul-fon-ate. [Boliden Intertrade] Sulfonates wetting agent antifoam, corrosion inhibitor, coupler, solubilizer, emulsifier for cement food, commercial laundry, cosmetics, fertilizers, insecticides, leather, paper, petroleum, and rubbtf processing, met cleaning, electr(q)lating, pickling. 

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