Boliden Aktiebolag

Karl-Axel Melkersson

Karl Goran Gorling

Ingvar A Edenwall

Hans Ivar Elvander

Douglas Sewerin Ekman

Johan E Wiklund

Carl Johan Hellestam

Bo G Hedenas

Thore R Johansson

The invention comprises a method of wet-cleaning gases containing sulfur dioxide, halogens together with arsenic and/or arsenic compounds obtained in a pyrometallurgical treatment of sulfidic materials. The gases are washed in a diluted sulfuric acid circulating in a closed circuit, from which arsenic is recovered. The gases are then cooled to water condensation whereby the halogens are substantially completely taken up in said condensate and separated. The separated condensate is then discharged to a recipient after precipitation of residual arsenic and neutralization.

Method of wet-cleaning gases containing sulfur dioxide, halogens and

There is provided a method of producing a partially reduced product from finely divided metal oxide containing material. The product is suited for continued reduction and the material containing the metal oxide may be an ore concentrate or an oxidic intermediate product. The material is charged to the top of a metallurgic shaft and is contacted during its fall through the shaft with hot gases of combustion, so as to melt said material. At the same time, a carbonaceous or carbon-containing reductant is charged to the furnace, such that said molten material is converted into a partially reduced product containing solid carbon material.

Method of producing a partially reduced product from finely-divided

The invention relates to a method of purifying sulphuric acid containing mercury in a plant for the production of sulphuric acid according to the contact process which involves drying moist roaster gases containing sulphur dioxide in at least two drying towers where the major part of the water content is absorbed in the first drying tower. The sulphuric acid containing mercury is in a quantity suitably measured to maintain the concentration between 70 and 80 percent by weight led to the first drying tower. To the second drying tower is led a sulphuric acid so that the concentration can be maintained between 95 and 103 percent by weight. The mercury is separated from a partial current from the circulating sulphuric acid in the first drying tower.

Method for the purification of sulphuric acid containing mercury

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Helsingborg, Sweden

Karl-Axel Melkersson