Studies on Utilization of Byproduct Gypsum from Salt Making Plants

NAGAI Shoichiro, FUKUMORI Yasushi

doi:10.11457/swsj1950.10.5_194

In the present paper were reported the results of various studies on utilization of byproduct gypsum material, which are called as “Gomi” and “Scale” and have the main compositions of NaCl and CaSO₄ mixed with MgCI₂, KCI, MgSO₄, K₂SO₄, Na₂SO₄, etc. These gypsum containing byproducts were firstly washed with sea water or dilute brine to dissolve and exclude NaCI and other salts above mentioned. CaSO₄ in these byproducts “Gomi” and “Scale” was proved to be of anhydrour form, which is called as soluble anhydrous gypsum, owing to the high boiling temperature in the concentrated brine solution. This soluble anhydous gypsum (CaSO₄) changed easily to the crystal gypsum (CaSO₄·2H₂O), by treating with dilute NaCI solution, which is the dissolving solution to separate out NaCI, KCI, MgCI₂, MgSO₄, K₂SO₄, etc. above mentioned.<BR>Crystalgpysum (CaSO₄·H₂O), thus obtained, was mixed homogeneously with calcined dolomite powder and slaked with proper amount water, and obtained special gypsum dolomite plaster (called by the present authors as “Gypster”), by the following equation. This special gypsum dolomitegypster (Gypster) was proved io be superior plastering material, x (CaSO₄·2H₂O)+(1-x)(CaO+ MgO)+y H₂OxCaSO₄·1/2H2O+(1-x)[Ca(OH)₂+Mg(OH)₂] by various testing methods of various plasters.<BR>This purified crystal gypsum or its cr ude raw material “Gomi” or “Scale” was mixed with raw dolomite in proper proportion and this mixture was calcined at about 900°C and then slaked with water of proper amount to special gypsum dolomite plaster. This poduct was also proved to be useful as plastering material of superior quality.

Studies on Utilization of Byproduct Gypsum from Salt Making Plants

Bibliographic Information

Description

Journal

Details 詳細情報について

Export

Report a problem