PL97654B1 - METHOD OF MANUFACTURING CELLULAR CONCRETE PRODUCED ON THE BASIS OF FLY ASH - Google Patents

Description

The subject of the invention is a method of producing aerated concrete produced on the basis of fly ash. The known method of producing aerated concrete based on fly ash consists in the fact that a part of the aggregate, which is unground fly ash, is mixed in appropriate proportions by weight with a fine hydraulic binder of composition: fly ash, which is the remainder of the aggregate, lime, cement and gypsum stone as well as with water and a raising agent, and then the mass is subjected to appropriate maturation and hardening methods. The use of gypsum stone, which is one of the basic raw materials for the production of cellular concrete according to of known methods, it is necessary due to the role it plays in the course of the technological process, where it is a regulator of the time of rising and bonding of the mass, and moreover, it is a component that ensures proper strength, reduces shrinkage and improves frost resistance of aerated concrete produced on the basis of fly ash. Pile The important gypsum stone is characterized by a relatively low quality - clay and soil are contaminated and its humidity often exceeds 10% (required max. 5%). High humidity causes difficulties in gypsum dosing, lime hydration during grinding in the mill and harmful increase of the temperature of the binder mixture. The aim of the invention is to eliminate the above-mentioned disadvantages and inconveniences. It has been found that the use of phosphogypsum - - waste generated during production in the production of aerated concrete based on fly ash phosphorus fertilizers will eliminate technological disturbances that are burdensome for plants and will affect the overall improvement of the quality of finished products, moreover, it will allow for a change in the technological process, consisting in a significant simplification of the gypsum sequence by eliminating the process of crushing and co-grinding with other binder components, which in turn will increase the efficiency According to the invention, phosphogypsum is introduced directly into the mixing water mixer before the aggregate and the binder mixture consisting of fly ash, cement and lime are introduced into the mixer. Phosphogypsum is introduced in loose form or as a slurry, i.e. a mixture of phosphogypsum with water.2 97 654 Phosphogypsum is characterized by a very high fineness of the order of 3500-5000 cm2 / g. It is generated as waste in the production of phosphorus fertilizers from aparites and phosphates as a result of treating them with sulfuric acid according to the scheme: Ca10F2 (PO4) 2 + 10H2SO4 + 10nH2O 6H3P04 + 10CaSO4 • nH20 + 2HF where: n = 0, 1/2 or 2 waste is considerable * 5k per one ton * of phosphoric acid, 5.5 tonnes of phosphogypsum are produced. These are burdensome waste, posing a threat to the environment. In the technological process of cellular concrete production based on fly ash, phosphogypsum is introduced as a sludge with an appropriate volumetric weight or in a loose (dried) form according to specific recipes directly into the mixing mixer, where it is mixed with other ingredients. PL

Claims (2)

Claims 1. The method of producing aerated concrete produced on the basis of fly ash, characterized by the use of a phosphogypsum additive, which, before being introduced into the mixer, of the aggregate and the binder mixture, consisting of fly ash, cement and lime, is introduced directly into the mixer for mixing water. 2. The method according to claim The process of claim 1, wherein the phosphogypsum is used in the form of a loose or slurry. and Prac. Typographer. UP PRL, circulation 120 + 18 Price PLN 45 PL