GB435763A - A process and method for the production of a soluble synthetic basic slag fertiliser - Google Patents

Abstract

A soluble basic slag fertilizer is obtained by melting together phosphate rock with such quantities of a silicious slag or a silicious slag forming material that the finished product will have a silica content of 12--40 per cent, the resulting mass being submitted, whilst still in the molten state, and within the furnace or other holder, to the action of streams of hot or cold air or of superheated steam, or a mixture of air and steam, or to the action of an oxidizing flame, directed under pressure through the molten mass so as to cause agitation thereof. The air may be enriched with oxygen. The slag forming material may be limestone with a high silica content or limestone with the addition of free silica or blast furnace or like slag. Other additions to the charge may be iron oxide, preferably added in the form of scrap iron, alumina, magnesia and alkalies. The melting process may be conducted in an electric furnace or reverberatory or open hearth furnace but is preferably carried out in a rotary furnace provided at its outlet end with an increased diameter constituting a chamber in which a bath of molten slag is formed which is subjected to the above described treatment. The Specification as open to inspection under Sect. 91 comprises also directing the above referred to gases upon the molten material. This subject-matter does not appear in the Specification as accepted.ALSO:A soluble basic slag fertilizer is obtained by melting together phosphate rock with such quantities of a silicious slag or a silicious slag forming material that the finished product will have a silica content of 12-40 per cent, the resulting mass being submitted, whilst still in the molten state, and within the furnace or other holder, to the action of streams of hot or cold air or of superheated steam, or a mixture of air and steam, or to the action of an oxidizing flame, directed under pressure through the molten mass so as to cause agitation thereof. The air may be enriched with oxygen. The slag forming material may be limestone with a high silica content or limestone with the addition of free silica or blast furnace or like slag. Other additions to the charge may be iron oxide, preferably added in the form of scrap iron, alumina, magnesia and alkalies. The melting process may be conducted in an electric furnace or reverberatory or open hearth furnace but is preferably carried out in a rotary furnace provided at its outlet end with an increased diameter constituting a chamber in which a bath of molten slag is formed which is subjected to the above described treatment. The Specification as open to inspection under Sect. 91 comprises also directing the above referred to gases upon the molten material. This subject-matter does not appear in the Specification as accepted.