| 摘要 |
<p>Elemental arsenic or its compounds are removed from solids, e.g. poisoned catalysts, pyrites and nickel ores, by passing a stream of hydrogen sulphide and steam or inert gas through the solid at 300-750 DEG C., thus forming arsenic sulphide which is volatilized from the solid. The reaction is preferably carried out by fluidizing the particulate solid in the stream of hydrogen sulphide and steam or inert gas. Example (1) refers to a poisoned alumina/nickel sulphide / tungsten sulphide catalyst being treated at 500 DEG C. in a vertical furnace fitted with a box having transverse baffles which collect the arsenic sulphide entrained in the effluent gases. Example (2) refers to arsenic containing pyrites being treated at 550 DEG C. with hydrogen sulphide and nitrogen. Examples (3) and (4) refer to a sulphur free nickel ore and pyrites being treated with hydrogen sulphide and steam at 700 DEG C.ALSO:Spent catalysts, e.g. alumina/nickel sulphide/tungsten sulphide, are freed from arsenic by contacting with a flow of hydrogen sulphide and steam or an inert gas at 300-750 DEG C. The catalyst may be fluidized by the reacting gas stream.</p> |
