RU2032748C1 - Method for processing hides of cattle - Google Patents

Abstract

FIELD: processing of hides of cattle. SUBSTANCE: washed hides are treated by solution which contains sodium sulfide, ammonium sulfate and calcium-containing waste , quantity of said solution is 60-120 kg per 1 t of origin material, dispersity of reagents being 1-50 μm/в. Proposed solution contains (mass % ): CaO 30-70, Mg O 2-5, Na₂O 0.1-2, K₂O 2-17, SiO₂ 8-22, Fe₂O₃ 0.5-5, Al₂O₃ 1-10, MnO 0.1-0.5, SO₃ 1-17, F₂O₅ 0.2-1, active sorbents 3-40, sulfide compounds of sulfur 0.3-2. EFFECT: improves efficiency of the method. 1 tbl

Description

 The invention relates to the leather industry and can reduce the cost of leather while maintaining and improving their quality.

 The skins are prepared for galling using standard technology, namely, they are washed, soaked, the spent solution is poured out, and ash liquid is poured into the drum. As an ash liquid, a solution containing sodium sulfide, ammonium sulfate and calcium compounds is used.

 A known method of treating cattle hides, including washing, soaking, gelling with a solution containing sodium sulfide, ammonium sulfate and calcium-containing waste from the production of shale ash.

 The purpose of the invention is to reduce the cost of leather while maintaining and improving their quality.

This goal is achieved in that finely dispersed reagents with a particle size of 0.1-50 microns in an amount of 60-120 kg per 1 ton of raw material containing the following ratio of components, wt. CaO 30-70, MgO 2-5; Na ₂ O 0.1-2, K ₂ O 2-17, SiO ₂ 8-22, Fe ₂ O ₃ 0.5-5; Al ₂ O ₃ 1-10; MnO 0.1-0.5; SO ₃ 2-17; P ₂ O ₅ 0.2-1, active sorbents 3-40, sulfide sulfur compounds 0.3-2.

As calcium-containing waste (KAMK), cement dust from electrostatic precipitators and coal ash from their burning is used TU 3470-10347-81. In shale ash, calcium compounds in the amount of up to 70% consist of free CaO 20% α CaO β SiO ₂ 23% αCaO β SiO ₂ γ Al ₂ O ₃ 25% and in the CAMC reagent free CaO up to 60% which is formed due to the temperature difference processing reagents. Shale ash has a dispersion of 5-70 microns, and KAMK 0.1–50 microns, which improves the sorption properties of KAMK.

Shale ash has the following chemical composition: SiO ₂ 22% KAMK 16.1% SO ₃ 5.2% KAMK 7.1% K ₂ O + Na ₂ O in shale ash 5% in KAMK 18% The presence of titanium dioxide, carbonate groups in KAMKe improves the process conditions. The presence of coagulants, flocculants, and active sorbents in the composition of KAMK allows, in the process of dehairing, to clean the ashpit from fats, suspended substances that pollute the skin when precipitated in the form of solid particles. The composition of KAMK includes more than 30 types of chemical elements and their compounds that modify the chemical activity of KAMK.

The finely dispersed composition of KAMK, the presence of oxidation catalysts, for example, MnO, such compounds as Fe ₂ O ₃ , Al ₂ O ₃ , which under certain conditions can serve as tanning agents for the skin, without interfering with the main task of hair removal and ashing, create comfort elements for skins, increasing them quality of workmanship.

 The proposed method is as follows.

A suspended KAMK solution is prepared in an ash tank based on the concentration of the sum of the oxides of calcium, potassium, sodium, magnesium, rubidium, cesium, lithium, and a fraction of up to 25 g / l. KAMK consumption is 60-120 kg per ton of raw material, depending on the type of leather. Sodium sulfide up to 14 g / l and ammonium sulfate up to 2 g / l are added to the solution. The skins are pre-soaked, washed and the ash composition prepared according to the above recipe is poured into a drum for dehairing. Liming is carried out with an LCD = 1.3-1.5, temperature 20-23 ^{° C} for up to 12 hours at a rotating speed of 2-3 revolutions / min, continuously controlling the degree nazhora leathers.

 The hair removal process is accelerated by up to 15% due to the active absorption of alkaline agents and loosening of the nails, improving the quality of the nails and finished skins. It should also be noted that skins dressed according to the proposed technology have the ability to actively absorb sodium sulfate.

 Physico-mechanical properties of leathers produced by the proposed technology and prototype are shown in the table.

 In the process of dehairing, the consumption of sodium sulfide occurs more than two times more intensively when using CAMC than lime, i.e. at initial concentrations in drums with KAMK and ash, respectively, 9.8 g / l and 10.1 g / l, after 1 h, the content of sodium sulfide became 3.4 g / l and 5.7 g / l, in the spent ash pan 1, 7 g / l and 3.5 g / l, which indicates a reduction in this reagent in the original ash pan and a reduction in process time. When machining leathers, skin, doubling of changes was not found. The preparation of an ash pan in a chemical workshop using KAMK can reduce labor costs, energy consumption and free up equipment, further reduce the cost of wastewater treatment.

 Thus, the concentration and integral of the alkaline titer, the presence of tanning agents and sulfide groups, activating the process of dehairing using CAMC, differs from known technologies.

Claims (1)

 METHOD FOR PROCESSING CATTLE SKINS, including washing, soaking, gelling with a solution containing sodium sulfide, ammonium sulfate and calcium-containing production waste, characterized in that finely dispersed reagents with a particle size of 0.1 to 50 μm in an amount of 60 120 kg per 1 t of raw materials containing the following components in the ratio, wt. CaO 30 70
MgO 2 5
Na ₂ O 0.1 2
K ₂ O 2 17
SiO ₂ 8 22
Fe ₂ O ₃ 0.5 5
Al ₂ O ₃ 1 10
MnO 0.1 0.5
SO ₃ 2 17
P ₂ O ₅ 0.2 1
Active sorbents 3 40
Sulfide compounds of sulfur 0.3 2

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