SU63999A1 - The method of obtaining a binder, for example, for molding in core mixtures - Google Patents

Description

The method of obtaining a binder, for example, for molding

and core mixes

Filed on May 14, 1943 in the Narkomlegprom for L ° 4016 (319947) Published on August 31, 1944

In the production of pulp from wood by the sulphite method, sulphite cellulose liquor, consisting mainly of calcium salts of lignosulphonic acids and sugars, is obtained as a waste. Sulfite cellulose liquors, processed by various methods and evaporated to the required concentration, are used as a fastener for molding and core mixtures in foundry. At present, these liquors are processed into alcohol, and the bard obtained as waste, processed according to existing and known methods to extract, cannot be used as a keeper in the foundry business due to its insufficient binding ability.

To increase the sulphite-cellulose stillage binding capacity or extract obtained from it, it is proposed to introduce sodium sulphate into it, which is sufficient to be taken in quantities less than necessary to precipitate all calcium stillage in the form of gypsum. Untreated bards extract gives a mixture with a tensile strength of 1.02 kg / cm, an extract from

bards treated with sulfate l sodium at the rate of 25% CaO precipitation gives a mixture with a tensile strength of 1.70 kg / cm-, and when precipitating 50% CaO, the tensile strength reaches 2.48 kg / cm-.

Thus, the proposed method allows to obtain extracts that meet the requirements imposed on the quality of the latter by the foundries of the engineering industry, and, therefore, makes it possible for extract plants to use bard of sulfite alcohol factories instead of lye.

Example. Barda, previously neutralized with lime milk, if its pH is below 5.0, is fed to the residue, which is adjusted to the density of the liquid extract in 150-IGO Brk. The stripped bard is collected in a defecator in which the liquid extract is heated to 90-95 ° C and treated with sodium sulfate to remove 25% of the CaO of the total amount contained in the extract.

The addition of sulfate and the transfer of the liquid extract are carried out in

Xfi 63999

for one hour. The sulfate is ground before use.

From the defecator, the liquid extract together with the precipitated gypsum is fed by a centrifugal pump to a filterpress. The resulting filtrate is collected in collections, and the gypsum residue on the napkins is removed through a bunker and tray into a special receiver installed near the production building.

The filtrate is settled in the collections for two hours, after which it is fed to the Kestner apparatus, from which the finished extract is, with a moisture content not exceeding 22.0,% is poured into drawers or boxes.

Subject invention

Claims (2)

1. A method of obtaining a binder, for example, for molding and core mixtures, from alcoholic sulphite cellulose bards, characterized in that sodium sulphate is introduced into the bard, with the aim of increasing its adhesive capacity, and then evaporated with preliminary separation of the deposited gypsum secession thereof. 2. The method according to claim 1, wherein the sulfate is injected in an amount insufficient to precipitate all the calcium bards in the form of gypsum, is carried out.