PROCESS FOR THE PRODUCTION OF A HYDRAULIC MORTAR OR CONCRETE

摘要

1521019 Slag-based mortar or concrete SOLVAY & CIE 20 May 1977 [24 May 1976] 21326/77 Heading C1H In a process for the production of an hydraulic mortar or concrete by mixing together an hydraulic binder (comprising a metallurgical slag), water, a slag-activating agent, and any supplementary ingredients, e.g. filters and additive materials, the activating agent and water employed are constituted, at least in part, by a waste aqueous suspension taken from a distillation column employed in the ammonia soda process, preferably in a concentrated form containing 20 to 60% by weight of solids. The waste products may comprise aqueous solutions of calcium chloride and sodium chloride containing in suspension various insoluble compounds, especially calcium aluminate, calcium silicate, calcium carbonate and calcium sulphate. Some silica, iron oxides and calcium hydroxide may also be present. Tables 2, 7, 8 and 10 of the Specification set forth the chemical composition of some sludges from soda works that may be used. The slag may be a granulated blast furnace basic slag ground to a fineness of 1000 to 8000 Blaines. Fillers include sand, fly ash, Portland cement, gravel, fibres, and synthetic polymer fibrids together with a polymeric wetting agent. Specified conventional additives may be included. A process for the production of a non-cellular rigid constructional material involves pouring the hydraulic mortar or concrete into a shuttering and allowing the mortar or concrete to set and harden. Preferred compositions comprise 75 to 1000 parts (by weight) of slag and 200 to 1500 parts of siliceous filler mixed with that amount of the waste aqueous suspension which contains 100 parts of solids, the resulting mixture being made up with any necessary additional amount of water to form a mixture containing 100 to 400 parts of water. A process for the production of a cellular rigid constructional material involves forming a shaped body using the hydraulic mortar, allowing the shaped body to expand and set, and thereafter baking and autoclaving. The expansion and setting of the mortar may take place at an elevated temperature of 40‹ to 100‹ C., and the autoclaving at 100‹ to 200‹ C., in the presence of steam, under a pressure of 5 to 20 kg./cm.2. Preferred compositions for the cellular mortar comprise 10 to 70% (by weight) of the suspension solids, 0À03-1% of pore-forming agent (hydrogen peroxide, or powdered aluminium or zinc) and 15 to 80% slag, the remainder of the solids, typically 10-60%, being made up by the siliceous filler and any additive included, and the total amount of water present being 30 to 200% of the total weight of the solids.