RU-2861419-C1 - METHOD FOR PRODUCING CEMENT WITH REGULATED WATER SEPARATION

RU2861419C1RU 2861419 C1RU2861419 C1RU 2861419C1RU-2861419-C1

Abstract

FIELD: cement. SUBSTANCE: invention relates to the production of silicate binding materials, to cement production technology. A method for producing cement with regulated water separation includes weight dosing and joint grinding of components. Clinker and part of gypsum, in the range of 0 < SO 3 £ 4.0 mas.% in terms of SO 3 , are dosed, and the mixture is jointly ground in vertical roller mills to a specific surface area of 250-500 m 2 /kg. In parallel, gypsum is ground to a specific surface area of 500-800 m 2 /kg and complete passage through a 02 sieve. Alternatively, the mixture is ground in ball tube mills to a specific surface area of 250-500 m 2 /kg, then ground gypsum with a specific surface area of 250-500 m 2 /kg is introduced in the range of 0 < SO 3 £ 4.0 mas.% into the jointly ground mixture of clinker and gypsum so that the cement contains SO 3 £ 4.0 mas.%, and then mixed. EFFECT: regulation of cement water separation processes by fully or partially introducing the ground part of gypsum (taking into account the total gypsum content in the cement in terms of SO 3 £ 4.0 mas.%) to the clinker. 1 cl, 1 dwg, 12 tbl

Inventors

Mishin Dmitrii Anatolevich
Erygina Alena Olegovna
Tarallo Zakhar Vladislavovich
Konovalov Vladimir Mikhailovich

Dates

Publication Date: 20260505
Application Date: 20251119

Claims (1)

A method for producing cement with controlled water separation, including weight dosing and joint grinding of components, characterized in that clinker and part of the gypsum, in the range of 0 < SO 3 ≤ 4.0 wt.% in terms of SO 3 , are dosed, the mixture is jointly ground in vertical roller mills to a specific surface of 250-500 m 2 /kg, and the gypsum is simultaneously ground to a specific surface of 500-800 m 2 /kg and completely passes through a 02 sieve; or the mixture is ground in ball tube mills to a specific surface of 250-500 m2 /kg, then crushed gypsum with a specific surface of 250-500 m2 /kg is introduced, crushed gypsum is introduced in the range of 0 < SO3 ≤ 4.0 wt.% into the jointly ground mixture of clinker and gypsum, so that the cement contains SO3 ≤ 4.0 wt.%, then mixed.

Description

The invention relates to the production of silicate binders and to cement production technology. Not only the cement industry, but also the concrete industry is interested in producing cements with the ability to regulate their water separation and high strength characteristics of hardened structures. A method for producing Portland cement by jointly grinding clinker and natural gypsum rock in a ball mill is known [Luginina I.G. Chemistry and chemical technology of inorganic binders: In 2 parts. - Belgorod: BSTU Publishing House, 2004. Part II. - P. 37]. This method is widely known and is used in all cement plants for the production of both ordinary and special types of cement. The disadvantage of the known method is the uncontrolled process of water separation of cements and, accordingly, low strength indicators of hardened products. In [Normantovich A.S. Regulation of the process of water separation of cement-water dispersed systems: specialty 05.17.11 "Technology of silicate and refractory non-metallic materials": dissertation ... candidate of technical sciences / Normantovich Anton Stanislavovich; Belgorod. state technological University named after V.G. Shukhov. - Belgorod, 2005. - 130 p.] it is stated that the water separation of the cement paste depends on the amount and type of gypsum introduced into the clinker during grinding. The less gypsum is introduced into the clinker, the lower the water separation of the cement. The disadvantages of this method also include the impossibility of regulating the process of water separation of cement and the impossibility of using special types of cement with different mineralogical composition in production. A method for producing cement is known (SU Patent for Invention No. 881039, published November 15, 1981, Bulletin No. 42). Cement production by this method involves separately adding a hydraulic additive to previously co-ground clinker and gypsum. This addition of the hydraulic additive alters the initial contact conditions of the cement components (clinker, gypsum, and additives), which in turn affects the rate of hydration of the clinker minerals and their interaction with the gypsum in solution. Changing the contact conditions during initial hydration affects the properties of the hardening samples. The compressive strength of cements produced by this method increases both early and late in the hardening process. The disadvantage of the analogue is the narrow studies of only the strength properties of the resulting cements, as well as the complexity of the production processes. The closest technical solution, adopted as a prototype, is a method for producing new types of cements used in construction, including mortars and concrete (RU Patent for Invention No. 2496728, published October 27, 2013, Bulletin No. 30). This method reduces water loss from Portland cements by adding NaF during the combined grinding of clinker and gypsum to a specific surface area of 300-400 m2 /kg. The disadvantage of the prototype is the uncontrolled process of water separation of cements and, consequently, the low strength of hardened products. It is important to note that gypsum is ground to different specific surfaces in different grinding units. For example, in a ball tube mill, gypsum is ground to sizes much smaller than the size of clinker particles, while in vertical roller mills there are many gypsum particles comparable to the size of clinker particles. In [Zlobin I.A. Formation of cement properties in various grinding systems: specialty 05.17.11 "Technology of silicate and refractory non-metallic materials": author's abstract. diss. ... cand. sci. / Zlobin Igor Alekseevich; Belgorod. state techn. univ. im. V.G. Shukhov. - Belgorod, 2016. - 18 p.] it was established that during industrial grinding in a ball tube mill, gypsum has a higher specific surface area than when ground in a vertical roller mill (gypsum is characterized as coarsely ground). The invention is aimed at regulating the processes of cement separation by gradually introducing gypsum into the clinker and grinding it. This is achieved by the fact that the method for producing cement with controlled water separation includes weight dosing and joint grinding of components, wherein clinker and part of the gypsum, in the range of 0 < SO 3 ≤ 4.0 wt.% in terms of SO 3 , are dosed, the mixture is jointly ground in vertical roller mills to a specific surface of 250-500 m 2 /kg, and in parallel the gypsum is ground to a specific surface of 500-800 m 2 /kg and completely passes through a 02 sieve; or the mixture is ground in ball tube mills to a specific surface of 250-500 m2 /kg, then crushed gypsum with a specific surface of 250-500 m2 /kg is introduced, crushed gypsum is introduced in the range of 0 < SO3 ≤ 4.0 wt.% into the jointly ground mixture of clinker and gypsum, so that the cement contains SO3 ≤ 4.0 wt.%, then mixed. The proposed method changes the reactivity of gypsum, which makes it possible to regula