RU1793479C - Current-conducting material - Google Patents

Description

Placeholder 1-3

Hydrated

silicate substance unstable

crystalline

structures

In the known material, during the hydration of Portland cement on the surface of the electrically conductive particles that make up the electrically conductive material, a gel-like film with a thickness of 10-20 μm is formed, which reduces the number of metal contacts that ensure the passage of electrically transfer processes, thereby reducing electrical conductivity and its stability.

In the proposed material, achieving the goal is related to the principle of contact hardening. The processes of structure formation in the claimed material are not related to the hydration of the components, but are determined by the physical contact4 interaction between the hydrated silicate substance and the metal particles, while preserving their chemical identity when the dry mixture of components is combined.

As a result of this, the number of metal contacts formed during the packing of metal particles remains unchanged, which increases the electrical conductivity of the composite compared to the prototype. With long-term storage of the material, the absence of hydration processes eliminates the change in the electrical properties of the compositions.

The decrease in the average density of the material is achieved by the fact that the hydraulic silicate substances used are characterized by lower density values (Gorshkov BC, Timashev VV, Savelyev VG Methods of physicochemical analysis of solid substances. - M.: Higher School, 1981 , p.335) in comparison with anhydrous analogues. The use of substances with reduced true density values provides a reduction in the average density of materials based on them.

An electrically conductive material containing less than 10% by weight of grinding and dressing sludge is characterized by low electrical conductivity in the range of 109-1013 Ohm cm and is practically dielectric, and containing more than 70% by weight of grinding and dressing sludge has low structural strength. In this case, the molding mixture loses its plasticity, as a result of which pressing is difficult due to the increased tendency to repress and crack formation.

As a silicate component of an electrically conductive material, silicate compounds are used, obtained on the basis of the following substances: anhydrous substances of an unstable crystalline structure represented by alkaline, alkaline-alkaline-earth and alkaline-earth mineral systems, these include known solidification and hydration hardening, as well as by-products of production such as granulated blast furnace and electrothermophosphorus slag, nepheline sludge, fuel ash from the burning of shale and other substances,

5 possessing in a dispersed state contact condensation properties and, in addition, capable of self-hydration with water with the formation of an unstable system of water formations

0 structure; anhydrous mineral formations of natural origin, represented by granite, nepheline, mariupolite, perlite, liparite, basalt, silica, flask, tripoli, etc., and

5 also by industrial wastes: fuel slags and ashes, burnt rocks, etc., capable of interacting with oxides of i-flux and alkaline earth metals with the formation of these hydrosilicates

0 metals with contact condensation properties after partial or complete dehydration.

As an electrically conductive component, polished slurry sludge (SHDS) is used, which is a grinding waste of metal products containing in the composition of the solid part a metal powder with a particle size of not more than 300 μm in an amount of 60-70 wt.% And

0 particles of abrasive (mainly represented by oxides of aluminum and silicon) in an amount of 30-40 wt.%. The fluid is constituted by the components of the cutting fluid. Sludge moisture after

5 filtration 40-46%.

As a filler, any of the aggregates traditionally used in concrete leading is used. The frictional composition of the aggregate is determined in each

0 individual case, the outcome of the size of the manufactured product. The dielectric filler accumulates the thermal energy released in the material.

Production process

5 of the electrically conductive metal silicate material consists of the following operations: mixing the components and molding by pressing. The molding is carried out by the method of cold bilateral pressing in metal molds

with a polished inner surface at a pressure of at least 20 MPa. The metal particles under pressure form a conduction frame, and the hydrated silicate substance, distributed upon pressing, fills the space between them, creating a conglomerate of a cluster structure.

In order to demonstrate the advantages of the invention, a metal-silicate conductive material was prepared containing, as a metal component, an SDS, and as a silicate substance of an unstable crystalline structure, dispersed calcium hydrosilicates (SC) of a composition of 0.8 CaO SI02 pNaO, natural analcime of the composition NaaO 45X2 x х2Н20, nepheline sludge from the Achinsk Alumina Refinery during heat-moisture treatment at 90-95 ° С.

Silica sand with a particle size of not more than 5 mm, corresponding to GOST 6139-78, with a content of silicon oxide (SlCte) of at least 98%, and content of silty, clay and dusty impurities of not more than 1% was used as filler.

Samples-cylinders of electrically conductive material were obtained by double-sided cold pressing of a dry mixture of components at a pressure of 100 MPa, size 32 x 32 mm.

The electrical resistance of the material was measured on a modified AC bridge R 577.

The compositions of the raw mixes and the test results are shown in the table.

The presented results indicate that the obtained electrically conductive material is characterized by high electrical conductivity in the range of 10-10 Ohm cm, the stability of its values in time and a reduced average density of the material in the range of 1.23 - 2.54 kg / cm3 in comparison with the prototype.

Claims (1)

SUMMARY OF THE INVENTION An electrically conductive material comprising a silicate binder, aggregate and an electrically conductive component, characterized in that, in order to increase electrical conductivity, ensure its stability and reduce average density, it contains a hydrated silicate substance of an unstable crystalline structure, and in conductive quality component-grinding-finishing sludge in the following ratio of components, May. %: Grinding and finishing slurry 10-70 Filler 1-30 Hydrated silicate substance of an unstable crystalline structure