RU2173306C2 - Method of preparing activated mineral powder for asphalt-concrete mixes - Google Patents

Abstract

FIELD: preparation of activated mineral powder for asphalt-concrete mixes used for building automobile roads and aerodromes. SUBSTANCE: method is carried out as follows; materials are compressed to state of agglomerate, and materials in combination with hot gases and activating mixture, are fed into deagglomeration zone followed by classification by dust separation of final product and recycle of substandard material to be further crushed. EFFECT: greater efficiency of process of preparing mineral powder and activation thereof, lower specific energy consumption.

Description

 The invention relates to the preparation of asphalt concrete and other bitumen-mineral mixtures used for the production of asphalt mixtures used for paving.

 A known method of preparing activated mineral powders for asphalt mixtures, including processing the raw materials during the grinding process with additives (brown coal tar, brown coal tar pitch or a mixture of brown coal tar and bitumen in a ratio of 1: 3 in an amount of from 2 to 2.5% by weight of raw materials), see a. from. USSR N 226451 class C 04 B, cl. 80 B 25/09, 1967

 The disadvantage of this method is the low quality of asphalt and other bitumen-mineral mixtures and large specific energy consumption.

There is also known a method of preparing asphalt concrete and other bitumen-mineral mixtures, taken as a prototype, comprising mixing a mineral material with an organic binder, such as bitumen and surface-active additives, while gravel or crushed stone used as a mineral material is previously crushed together with a binder together with a mixture of bitumen and a surfactant, introduced in an amount of from 0.5 to 3.0% by weight of mineral materials at a temperature of 50-180 ^o C (AS USSR N 226452 class C 04 B, class 80 B 25/10, 1967).

 The disadvantage of this method is the high specific energy consumption when grinding mineral materials and low productivity of the grinding process, which excludes the possibility of producing activated mineral powder on an industrial scale.

 The aim of the invention is to increase the productivity of the process of obtaining mineral powder and its activation, reducing specific energy consumption for grinding mineral materials.

 This goal is achieved by the fact that mineral materials are pressed to a state of agglomerate, and then, together with hot gases and an activating mixture, they are fed into a deagglomeration zone, where agglomerates heated, dried, coated with an activating mixture are fluffed, as well as fluffing products, followed by dust separation of the finished product product and returning under-ground material to regrind.

 Compaction of the mineral material to the state of agglomerate and subsequent deagglomeration in the presence of hot gases and an activating mixture make it possible to obtain a high percentage of the fraction corresponding to the finished product in the form of activated mineral powder.

 A method of manufacturing an activated mineral powder for asphalt mixtures is as follows.

 The mineral material, mainly carbonate rocks, is crushed by pressing to an agglomerate state, after which it is fed into the deagglomeration zone with hot gases and an activating mixture, where agglomerates are fluffed (crushed), mixing grinding products with an activating mixture in a hot gas stream, followed by dust separation of the finished product and the return of substandard material for regrinding.

 Execution example.

 After a one-time compression of limestone with a grain composition of 5-60 mm in a press-roll grinder with rolls with a diameter of 1400 mm, the crushed material has a particle size of up to 17 mm, the content of the fraction 0-0.1 mm is about 35%. After passing the agglomerate through a hammer mill in a stream of hot gas and an activating mixture, the content of the 0-0.1 mm fraction increases by 5-7%, and fractions of more than 1 mm decrease by 30-35%. After the classification process, activated mineral powder is isolated up to 40% corresponding to GOST 1657-78.

 The use of the invention allows to reduce energy consumption and labor costs for rough and fine grinding by 2-3 times depending on the properties of the processed material.

 The invention was created in the order of service assignment.

Claims (1)

 A method for the production of activated mineral powder, including drying, mixing with activating additives and grinding of mineral materials, characterized in that the mineral materials are pressed to a state of agglomerate, and then, together with hot gases and an activating mixture, are fed to the deagglomeration zone, followed by dust separation of the finished product and return of substandard material to regrinding.