SU814974A1 - Method of producing ceramic articles - Google Patents

Description

The invention relates to the manufacture of ceramic products from oxides, for example alumina, for mounting them on paper machines as wear-resistant parts, such as hydroplanks, and can be used in pulp and paper, light industry and other industries.

A known method of manufacturing ceramic products by wetting an alumina powder with a sulphite-distillery stillage with additional plasticization with a mixture of hydrochloric acid with an organic polymer, for example; methyl cellulose [1]. fifteen

However, the mechanical strength of the workpieces after drying is insufficient for their subsequent transportation and processing.

There is also a known method for the manufacture of ceramic products from a mixture of powdered oxide materials, for example alumina, by wetting them with reactive phosphoric acid. :

According to this method, after wetting, the alumina powder is thoroughly mixed, aged, briquetted, granulated and pressed.

The pressed workpieces are dried 30 at 200-400 ° C, subjected to mechanical processing and fired at 1750 ° C I. ·

The use of phosphoric acid as a binder provides high mechanical strength of the workpieces after drying (ex. = 500-60Ό to gm / cm ² ). this makes it possible to transport the workpieces without any damage, as well as to process the workpieces on turning and milling machines.

However, the pressed blanks before drying have low mechanical strength, which is why when they are removed from the molds and further transported to the drying chambers, they are easily destroyed.

The closest technical solution to the proposed one is a method of manufacturing refractory ceramic products based on aluminum oxide, comprising mixing finely divided alumina with a binder containing methyl cellulose and phosphoric acid in a ratio of'1: 1 to 1: 3, molding, drying and heat treatment [3] .

However, the total number of introduced ligament components, especially methyl3, to produce products that have cracks depending on cellulose leads to a large number of hydroplank cops after firing (5-50% of the amount of methylcellulose).

The purpose of the invention is to increase the yield of products.

This goal is achieved due to the fact that in the method of manufacturing ceramic products, comprising mixing fine-grained alumina with a binder containing methyl cellulose and phosphoric acid in a ratio of 1: 1 to 1: 3, molding, drying and heat treatment, the binder is introduced in an amount of 710 masses %, moreover, methyl cellulose is administered in an amount of 0.026-0.1 wt.% of the total mass in the form of a 1.5-2% solution.

The method is as follows.

A binder material (binder) is prepared - a mixture of phosphoric acid with a 1.5-2.0% solution of methylcellulose in a ratio of 1: 1 to 3: 1. The resulting binder is introduced, in an amount of 7-10 wt.% In crushed alumina with a grain size of 0.5 microns. Mixing alumina with a bunch of produce on the mixing runners or other units. The resulting mass is passed through a sieve with a mesh size of 1 mm., After which the resulting press powder is subjected to aging for 3-5 days. _t briquetting at a specific pressure of 500-1000 kgf / cm? granulate to obtain a particle size of 0) 2-1 mm and preforms are pressed on a hydraulic press at a specific pressure of 500-100 kgf / cm. The pressed blanks are dried, processed on a milling machine to obtain the desired configuration, burned in a plasma furnace at 1750 ° C and ground.

Example 1. Alumina grade LGMK is crushed to a grain size of 0-3 microns, after which 7% of a binder consisting of a mixture of phosphoric acid and a 1.5% solution of methylcellulose in a ratio of 1: 1 (0.026 wt.% Of the total weight) is introduced . The resulting press powder is passed through a sieve with a mesh size of 1 mm, aged for 5 days, briquetted at a specific pressure of 500 kgf / cm ^, granulated to obtain a fraction of 0.2-1 m >

Editor V. Eremeeva zagopodverny fre1750 ^d C brand zero at a specific pressure of 1000 kgf / cm? The pressed bales are dried at 200 ° C, they are quenched by mechanical processing with a grain machine, burned at and ground.

Example 2. Alumina

GN-1 with the addition of 0.3% magnesium oxide is crushed to a grain size of 0-5 μm, after which 10% of a binder consisting of a mixture of phosphoric acid and a 2.0% solution of methylcellulose in a ratio of 3: 1 (0, 1 wt.% Of the total weight). The obtained powder is passed through a sieve with a mesh size of 1 mm, aged for 5 days, briquetted at a specific pressure of 1000 kgf / cm, granulated to obtain a fraction of 0.2-1 mm, granulate is pressed at a specific pressure of 1000 kgf / cm ² ·. The pressed blanks are dried at 200 ° C, machined on a milling machine, calcined at 1750 ° C and ground.

The strength of the workpieces after pressing is 60-70 kg / cm ¹ , and after drying at 200 ° C - 300-500 kg / cm.

The use of a new binder material eliminates marriage when removing preforms from the mold and transporting them to the drying chambers during the manufacture of ceramic hydroplanes for paper machines.

Claims (1)

Claim A method of making ceramic products, comprising mixing finely ground alumina with a binder containing methylcellulose and orthophosphoric acid in a ratio of from 1: 1 to 1: 3, molding, drying and heat treatment, characterized in that, in order to increase the yield of suitable products, the binder is introduced in the amount 7-10 wt.%, And methylcellulose is injected in the amount of 0.026-0.1 wt.% Of the total mass in the form of a 1.5-2% aqueous solution.