Recovery of cement kiln dust through precipitation of calcium sulfate using sulfuric acid solution
OwnerJerry F. Key, Jr.inventor
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Abstract
A method and apparatus for recovering calcium sulfate di-hydrate (gypsum) from a precipitation reaction between cement kiln dust and commercial, spent or waste grade sulfuric acid solution. The gypsum recovered from this process acts as a necessary functional additive for use in the production of hydraulic Portland cement. The invention advantageously provides for a method of producing a fertilizer as a byproduct of the gypsum production process. The invention also provides a method of producing Portland cement using the gypsum derived from the cement kiln dust.
Claims23
A method of producing gypsum from cement kiln dust, the method comprising the step of:
- reacting cement kiln dust, water, and a sulfuric acid solution to produce a gypsum product.
A method of producing cement using a gypsum product derived from cement kiln dust, the method comprising the steps of:
- reacting cement kiln dust, water, and a sulfuric acid solution to produce a gypsum product;
- drying the gypsum product;
- grinding and heating a raw material to produce a clinker wherein the raw material is selected from the group consisting of clay, shale, concrete, limestone, sand, mill scale, bauxite, fly ash, and combinations thereof;
- and
- cooling the clinker and then mixing and grinding the clinker with the gypsum product to produce the cement.
Dependencies are inferred from the claim text.