The present invention describes a method for manufacturing of a composite fixated material comprising the steps of: (a) providing bottom oil shale ash obtained after burning oil shale, said bottom oil shale (BOSA) comprises pozzolanic particles having size of about 10 to 4000 μm and being capable of adsorbing trace elements at their surface; (b) providing acidic waste comprising said trace elements; and (c) adding the BOSA provided in step (a) to the acidic waste provided in step (b) in amount of about 0.1-0.4 weight parts of said BOSA per one weight part of said waste, and mixing said waste with said BOSA, thereby obtaining a neutralised (scrubbed) precipitate with the fixated trace elements, wherein said neutralised (scrubbed) precipitate with the fixated trace elements constitutes said composite fixated material.

The present invention describes a method for manufacturing of a composite fixated material comprising the steps of: (a) providing bottom oil shale ash obtained after burning oil shale, said bottom oil shale (BOSA) comprises pozzolanic particles having size of about 10 to 4000 μm and being capable of adsorbing trace elements at their surface; (b) providing acidic waste comprising said trace elements; and (c) adding the BOSA provided in step (a) to the acidic waste provided in step (b) in amount of about 0.1-0.4 weight parts of said BOSA per one weight part of said waste, and mixing said waste with said BOSA, thereby obtaining a neutralised (scrubbed) precipitate with the fixated trace elements, wherein said neutralised (scrubbed) precipitate with the fixated trace elements constitutes said composite fixated material.

A method for producing supplementary cementitious material. The method comprises contacting a mineral stream with an acid to form an activated mineral stream; reducing the moisture content of the mineral stream; and comminuting the mineral stream to form a supplementary cementitious material. A method of extracting a metal from a mineral stream. The method comprises contacting a mineral stream with an acid to form an activated mineral stream; filtering the activated mineral stream to extract leach liquor comprising the metal; and neutralizing the acid.

A method for producing supplementary cementitious material. The method comprises contacting a mineral stream with an acid to form an activated mineral stream; reducing the moisture content of the mineral stream; and comminuting the mineral stream to form a supplementary cementitious material. A method of extracting a metal from a mineral stream. The method comprises contacting a mineral stream with an acid to form an activated mineral stream; filtering the activated mineral stream to extract leach liquor comprising the metal; and neutralizing the acid.