SU920020A1 - Raw material mixture for producing active mineral additive to cement - Google Patents

Description

The invention relates to mineral additives for the production of white and decorative cementing materials and can be used in the building materials industry. Active mineral supplements of natural and artificial origin are known 1. The closest in technical essence and the achieved effect to the invention is an additive consisting of electrothermophosphoric slag 21. However, in its whiteness, these active mineral additives do not meet the requirements for obtaining white Portland cement and other high-quality mortar materials. The aim of the invention is to increase the whiteness and activity of the additive. The goal is achieved by the fact that the raw material mixture for producing an active mineral additive, including electrothermophosphorus slag, additionally contains phosphogypsum or gypsum in the following ratio of components, May L: Electrothermophos 80-82, 9.1% slag Phosphogypsum or 18.1-20 gypsum Chemical composition of the raw materials used materials are presented in table. 1 .. Gypsum - calcium sulfate dihydrate (CaSo..2HnO) is used in the form of an analytical grade reagent. The mixture composed of electrothermophosphorus slag and phosphogypsum or calcium sulfate dihydrate (gypsum) in the ratio indicated in the table. 2, is fused at 1400-1 70 ° C and held for 10-30 minutes to assimilate the added additives and homogenize the melt, as well as complete the slag bleaching process by releasing phosphogypsum decomposition products or calcium sulfate dihydrate, after which the melt is poured into water. In the case of using electrothermophosphorus slag in a fire-liquid state, a bleaching additive (phosphogypsum or gypsum) is injected directly into the melt at 1400-H70-C. The whiteness coefficient is determined for the two groups of mineral additives obtained using an FM-58 visual photoelectric photometer on glass NS-14 and absorption of lime from lime mortar according to GOST 3 76-7. The data presented in Table. 2. Introduction to the slag mixture or to the melt of phosphogypsum or calcium sulfate dihydrate in an amount less than 18.1 weight increases the amount of the crystalline phase in the cooled product. An increase in the amount of the bleaching additive in excess of 20 wt.% Leads to a decrease in the whiteness of the active additive. As follows from the table. 2, the whiteness of the obtained granulated active additive is 9-16% higher than that of the initial granulated electrothermophosphoric slag and is 9399% for glass MC-I. According to the degree of absorption of lime from a known solution, the resulting active mineral additive is 5–13% higher than the activity of the initial granulated electrothermophosphoric slags. The method of introducing the bleaching additive into the mixture or melt does not significantly affect the properties of the resulting product. The use of the proposed blend to obtain a white active mineral additive improves the quality of white and decorative cements and reduces the cost of their production. Table 1

Electrothermophosphoric slag 47.61 1.36 3.66 1.2 0.3 2.1 2.1 Phosphogypsum 37.86 0.85 Next 0.24 0.07

The composition of the mixture, wt.%

Phosphogypsum

Slag

Sab 0

Known 100

2.8 0.97

100

table 2

Additive Activity by

Coefficient GOST 3476-74 whiteness,% (for glass MS-14)

CaO, absorbed 1 g of the additive, mg

for 15 titses 30 titles

22.72

45.30

85 1.27 0.3 47.21 12.20 100

Continuation of table 2

Continuation of table 2

Melt Exposure 20 min

Claims (1)

• claims _3J The raw material mixture’s to obtain an active mineral cement additive, including electrothermophosphoric slag, characterized in that, in order to increase the whiteness of 40 and the activity of the additive, it additionally contains phosphogypsum or gypsum in the following ratio, wt.%: Electrothermophosphoric slag 80-82.9 Phosphogypsum or gypsum 18.1-20