How decamerone tannery waste

 

(57) Abstract:

The method refers to the leather industry, namely the separation of chromium from tannery waste. The treatment of tannery wastes are consistently in the alkaline electrolyte and acid-salt solutions in two stages each. At the first stage alkali-salt processing the working solution is prepared with caustic soda solution by adding sulfuric acid. Acid-salt waste processing at the first stage leading to the solution containing H2SO4and Na2SO4formed by mixing part of the exhaust alkali-salt solution with a solution of sulfuric acid or with pre-adjusted waste solution of the second stage acid-salt processing the previous batch. In the second stage alkali-salt processing using pre-corrected exhaust solution of the first stage alkali-salt processing this batch. The technical result is the simplification and reduction of the duration of the technological process of decamerone, increase collagen and reduce energy consumption. 4 C.p. f-crystals, 1 table.

The invention relates to the leather industry and can Oia additional source of protein raw materials in the production of technical gelatin, mezdrovogo glue and protein feed additives.

There are various ways to decamerone waste leather chrome tanning.

The known method includes treatment of waste water slurry composition, g/l: hydrate the calcium oxide - 40-45; sodium carbonate - 4-5; surfactant - 0,3-0,4; water to 1 l, the ratio of the suspension and the mass of waste 3.5 to 4:1 and the temperature 36-46oC for 2-2 .5 hours, the extraction of chrome tanning agent is carried out in the presence of ammonium sulfate, with five extraction is carried out at 41-46oC, concentration of sulfuric acid and ammonium sulfate at each step, respectively, g/l: 60-70 20-25; 45-52 and 13-15; 24-30 and 8.5-10; 15-17 and 4-5; 7-8 and 2.0 to 2.5 and a ratio to the mass of waste 3.5 to 4:1, and re-extraction in two stages carried out five times at 25-29oC, concentration of sulfuric acid and ammonium sulfate, respectively, at each step of each phase, g/l: 30-35 10-15; 22-24 and 7-11; 14-16 and 6-7; 7-8 and 3.0-3.5; 3.5 to 4.0 and 1.5-1.7, and the ratio of the mass of waste 3.5 to 4:1 for 25-30; 20-25; 15-20; 12-15 and 10-12 min, respectively, at each step, the washing waste water and neutralization with ammonia or sodium carbonate to pH 6-7 [1].

A known method including pre-rinsing with water at 65-70oC for 10-15 min, delacey then add caustic soda in the amount of 90-100 g/l and continue processing within 4-4,5 hours at a temperature of 18-22oWith, washed with water at 30-32oC for 15-30 min, and the neutralization of conduct for 3-3,5 hours, first with a solution of ammonium sulfate in the amount of 60-80 g/l, in which after 10-15 minutes add sulfuric acid in the amount of 5-7 g/l [2].

Also known a process comprising the sequential processing of waste alkali and acid and alkaline treatment is carried out in a solution of caustic soda with a concentration of 110-130 g/l at 20-25oWith liquid ratio (LCD) 8 3-5 h, washed with water when the LCD=15 for 0.5 h, neutralized with sulfuric acid solution with a concentration of 30 g/l and a flow rate of 25% by weight of the waste if LCD= 2,25 to achieve a pH of 6.5 to 7.0, washed with water when the LCD=15 for 0.5 h, the acid treatment is carried out in the pickle solution containing, g/l: NaCl - 140-170, HCOOH - 8-16; H2SO4- 15-35, with 20-25oWith LCD=8 for 10-14 h, washed with water when the LCD=15 for 0.5 h, neutralized with sodium carbonate solution concentration of 120 g/l and a flow rate of 25% by weight of the waste if LCD=2,25 to achieve pH 7.0-7.5 and washed with water at LC=15 for 0.5 h, to achieve a low chromium content (0,77 g/kg) repeat cycle [3].

The disadvantages of these methods are: the use of a large number of chemicals, many what concentrations [1, 2, 3], which leads to peptization and hydrolysis of collagen, which in turn reduces the output of collagen (86-90% of theoretical).

It is known that in cold dilute acids and alkalis collagen swells. And every swelling is starting peptidase, leading to greater or lesser extent by the hydrolysis of collagen. With increasing concentration and increasing temperature also increases Paterswolde the action of acids and at the same time also gidrolizuemye their action. When alkalis, however, soon reached an area of concentration in which peptidase is already significant. Hydrolytic cleavage in the presence of alkali starts also at lower concentrations and at lower temperatures than is the case in the presence of acids.

That swelling is nothing like starting peptidase, especially clearly detected when the swelling in the presence of neutral salts, because under the action of neutral salts solutions at ordinary temperatures eliminates the phenomenon of hydrolysis [4].

It is known that the Halogens increase the hydrolysis gelievogo substances, while sulfates detain him more than water [5].

The determination of the number of the Peres is2SO4<HO<NaCl<NaCNS [6].

This is confirmed by hofmeisters rows of ions or lyotropic series, in which one by one reaching ions have a decreasing ability to cause swelling.

Lyotropic number of anions:

CNS-1-J-1-lO3-1-NR3-1-CL-1-C2H3O2-1-SO4-2.

Lyotropic number of cations:

CA2+-Li+1-Na+-K+-Rb+1-Cs+1[7].

Another purpose of neutral salts to lower the potential difference between the protein and the solution. For collagen required salt solution with a concentration of not less than 0.1 m [8].

In the case of use as a neutral salt of sodium sulfate concentration in the solution should be at least 14.2 g/l

The technical result of the invention are:

- simplify the process of decamerone due to the elimination of the intermediate leaching the treated waste and neutralised combined (simultaneous) with the main processes for the formation of a working solution of ions of a neutral salt is sodium sulfate, preventing peptidases mixing the treated waste;

- reduction of the duration of the process.

The technical result is achieved due to the fact that in the way decamerone tannery wastes, including their serial processing in the alkaline electrolyte and acid-salt solution, washing with water, neutralization, repeated washing and dehydration, characterized in that the alkali-salt and acid-salt processing is carried out in two stages each in alkaline-saline treatment use solution composition, g/l: NaOH - 20-25; Na2SO4- 15-18; water to 1 l, and for acid-salt treatment use solution composition, g/l: H2SO4- 45-50; Na2SO4- 15-18; water up to 1 l

At the first stage alkali-salt processing the working solution is prepared with caustic soda solution by adding sulfuric acid.

In the second stage alkali-salt processing using a spent solution of the first stage alkali-salt processing this batch, pre-adjusted to the content of NaOH 23-28 g/l, with the formation of a working solution of composition, g/l: NaOH - 20-25; Na2SO4- 15-18; water up to 1 l

Acid-salt waste processing on the first and second stages are on the East is avlee them in a solution of sulfuric acid with a concentration of 90-100 g/l, prior to the formation of a working solution of composition, g/l: H2SO4- 45-50; Na2SO4- 15-18; water up to 1 l

At the first stage of the acid-salt processing subsequent batch use the spent solution of the second stage acid-salt processing the previous batch, pre-adjusted to the content of H2SO465-73 g/l, with the formation of a working solution of composition, g/l: H2SO4- 45-50; Na2SO4- 15-18, water to 1 l

Alkali-saline solution for the first stage of processing to prepare the NaOH solution with a concentration 29-35 g/l, adding size 63-76 kg of sulfuric acid (98%) prior to the establishment of a working solution of composition, g/l: NaOH - 20-25; NaS4- 15-18; water to 1 L. the Processing carried out at 28-30oC, LC=4 for 2-2,5 hours periodic mixing: 1-2 minutes - stirring, 3-4 minutes rest.

Then part of the spent solution, component 60-62% of the original volume, poured into a storage tank for reuse in the second stage, and in the case of the first stage of the acid-salt treatment of spent acid-salt solution of the second stage acid-salt processing the previous batch is full.

2SO4- 45-50; Na2SO4- 15-18; water to 1 L. the Processing carried out at 28-30oC for 4-5 h in a periodic mixing: 1-2 minutes - stirring, 3-4 minutes rest.

The spent acid-salt solution is drained into the sewer.

In the second stage alkali-salt processing wastes are waste solution of the first stage, which is roughly correct (support) to the content of NaOH in it 23-28 g/l, with some caustic soda is consumed to neutralize sulfuric acid in waste after acid-salt processing with the formation of a working solution of composition, g/l: NaOH - 20-25; Na2SO4- 15-18; water up to 1 l

Processing is carried out at 28-30oC, LC=4 for 2-2,5 hours periodic mixing: 1-2 minutes - stirring, 3-4 minutes rest.

Part of the spent solution, component 60-62% of the original volume, poured into drains.

Acid-salt waste processing at the second stage, leading to a remaining portion of the spent alkali-salt solution, why add to it a solution of chamois is Drago soda with the formation of a working solution composition, g/l: H2SO4- 45-50; Na2SO4- 15-18; water to 1 L. the Processing carried out at 28-30oC for 4-5 h in a periodic mixing: 1-2 minutes - stirring, 3-4 minutes rest.

The spent acid-salt solution is poured into the storage tank for reuse in the first stage of processing subsequent batch.

Decamerone waste washed with water with a temperature of 28-30oWith LCD=4-8 (running water) for 30-35 minutes in a mode of constant stirring, neutralized to a pH of 6.5-7.5 with NaOH solution, again washed with water with a temperature of 18-20oWith unloaded in the perforated tape for dehydration and sent for further processing.

Example 1. In the apparatus (drum pendant type, screw or mixer) load 1500 kg trimmings tanned wastes with a moisture content of 60%, of the capacity of the storage and preparation of alkali-salt solution serves 6000 l of a solution with a temperature of 28oWith that composition, g/l: NaOH - 20; Na2SO4- 15; water to 1 l, which is prepared to 6000 l aqueous solution of NaOH with a concentration of 29 g/l, and adding thereto 63 kg of sulfuric acid (98%). The apparatus is put into rotation in periodic mode: rotating - 2 min rest 4 min

Total time on botany the solution of 3600 l is poured into the vessel preparation and storage of alkaline-saline, where its volume adjusted with water to 4500 liters and adjusted to a concentration of 23 g of NaOH/l

In the apparatus from the vessel preparation and storage of the acid-salt solution serves 3600 l of a solution containing 90 g/l H2SO4with the temperature of the 28oSince, in this part of sulfuric acid consumed in the neutralization of caustic soda remaining after partial discharge of the spent alkali-salt solution and caustic soda, which is in the liquid phase of the waste, the total volume of which is 2400 l, with the formation of sodium sulfate in solution is in the form of ions), as a result, taking into account the mutual dilution of these solutions and summing the volumes formed by the acid-salt solution in the amount of 6000 l, composition, g/l: H2SO4- 45; Na2SO4- 15; water to 1 L. the Apparatus is put into rotation in periodic mode: rotating - 2 min rest 4 min

The total processing time is 4 o'clock

After the specified time spent solution is drained into the sewer.

In the apparatus of the capacity of the storage and preparation of alkali-salt solution serves 4500 l corrected alkali-salt solution of the first stage of processing temperature of the 28oWith part of the caustic is by use of sodium sulfate in solution is in the form of ions), as a result, taking into account the mutual dilution of these solutions and the summation of the volumes, is formed of alkali-salt solution in the amount of 6000 l, composition, g/l: NaOH - 20; Na2SO4- 15; water up to 1 l

The apparatus is put into rotation in periodic mode: rotating - 2 min rest 4 min

The total processing time 2 hours

Part of the spent solution in the volume of 3600 l is drained into the sewer.

In the apparatus from the vessel preparation and storage of the acid-salt solution serves 3600 l of a solution containing 90 g/l H2SO4with the temperature of the 28oSince, in this part of sulfuric acid consumed in the neutralization of caustic soda remaining after partial discharge of the spent alkali-salt solution and caustic soda, which is in the liquid phase of the waste, the total volume of which is 2400 l, with the formation of sodium sulfate in solution is in the form of ions), as a result, taking into account the mutual dilution of these solutions and summing the volumes formed by the acid-salt solution in the amount of 6000 l, composition, g/l: H2SO4- 45; Na2SO4- 15; water up to 1 l

The apparatus is put into rotation in periodic mode: rotating - 2 min rest 4 min

2SO465 g/l, for re-use as an acid-salt solution at the first stage of processing subsequent batch.

In the apparatus pour 6000 l of water with a temperature of 28oS. the Apparatus result in continuous rotation for 10 minutes, then open the drain device for draining wash water in drains and simultaneously with the drain serves another 6,000 liters of water with a temperature of 28oC.

Rotation of the apparatus is continuous for 20-25 minutes until full bathtub drain.

Drain valve is closed. The apparatus serves 5000 l of water with a temperature of 28oC. the Apparatus is put into rotation and on-the-go offers a solution containing 29-35 g/l NaOH in the amount of (500-600 l) sufficient to achieve a pH of 6.5-7.5.

Rotation of the apparatus is continuous for 0.5 h

The tub is drained into the sewer.

In the apparatus pour water with a temperature of 18o(In summer, cold water with natural temperature) and are flush like the first.

Decamerone waste is unloaded in the perforated tape for dehydration and sent for further processing.

An example of the exercise and retention of alkali-salt solution serves 6000 l of a solution with a temperature of 30oWith that composition, g/l: NaOH - 25; Na2SO4- 18; water to 1 l, which is prepared to 6000 l aqueous solution of NaOH with a concentration of 33 g/l, and adding thereto 76 kg sulfuric acid (98%).

The apparatus is put into rotation in periodic mode: rotation - 1 min rest - 3 minutes

The total processing time of 2.5 hours

After the specified time processing waste humidity rises to 80%. The spent solution is poured into the vessel preparation and storage of alkali-salt solution, where its volume adjusted with water to 4500 liters and adjusted to a concentration of NaOH 28 g/L.

In the apparatus from the vessel preparation and storage of the acid-salt solution serves 4500 l corrected the acid-salt solution of the second development stage previous batch temperature 30oWith that composition, g/l: H2SO4- 73; Na2SO4- 18; water to 1 l, with part of the sulfuric acid is consumed in the neutralization of caustic soda, which is in the liquid phase of the waste in a volume of 1500 l, with the formation of sodium sulfate in solution is in the form of ions), as a result, taking into account the mutual dilution of these solutions and summing the volumes formed by the acid-salt solution in the amount of 6000 l, solovchenko mode: rotating - 1 min rest 3 min

The total processing time 5 o'clock

The spent solution is drained into the sewer.

In the apparatus of the capacity of the storage and preparation of alkali-salt solution serves 4500 l corrected alkali-salt solution of the first stage of processing temperature 30oWith part of the caustic soda is consumed to neutralize sulfuric acid in the liquid phase of the waste in a volume of 1500 l, with the formation of sodium sulfate in solution is in the form of ions), as a result, taking into account the mutual dilution of these solutions and the summation of the volumes, is formed of alkali-salt solution in the amount of 6000 l, composition, g/l: NaOH - 25; Na2SO4- 18; water up to 1 l

The apparatus is put into rotation in periodic mode: rotation - 1 min rest - 3 minutes

The total processing time of 2.5 hours

Part of the spent solution in the volume of 3600 l is drained into the sewer.

In the apparatus from the vessel preparation and storage of the acid-salt solution serves 3600 l of a solution containing 96 g/l H2SO4with temperatures 30oWith a portion of the spent acid to neutralize the caustic soda remaining after partial discharge of the spent alkali-saloobrazovanie of sodium sulfate in solution is in the form of ions), as a result, taking into account the mutual dilution of these solutions and summing the volumes formed by the acid-salt solution in the amount of 6000 l, composition, g/l: H2SO4- 50; Na2SO4- 18; water up to 1 l

The apparatus is put into rotation in periodic mode: rotation - 1 min rest - 3 minutes

The total processing time 5 o'clock

After the specified time spent solution is poured into the vessel preparation and storage of the acid-salt solution, where its volume adjusted with water to 4500 liters and adjusted to the concentration of H2SO473 g/l, for re-use as an acid-salt solution at the first stage of processing subsequent batch.

Then hold washing degronianum waste neutralization and re-washing as in example 1.

Thus, by eliminating the intermediate leaching the treated waste and carrying out the neutralization of the combined proceeding simultaneously with the main processes for the formation of a working solution of ions of a neutral salt is sodium sulfate, preventing peptization and hydrolysis of collagen, the technical solution of the invention is achieved:

- simplified igeni energy,

output of collagen was 95,8 - 96.9% of theoretical.

Reuse of waste alkali-salt and acid-salt solutions can reduce the consumption of chemical materials by 30-40% and reduce the burden on water treatment facilities.

In addition, the use of alkali-salt and acid-salt solutions in concentrations, temperature regimes and modes of mechanical impacts identified in the proposed method, decamerone tannery waste, allow to increase the output of collagen at 11-12,6%.

Data characterizing the comparative rates of processes decamerone tannery waste is given in the table.

Sources of information

1. USSR author's certificate 1240789, MKI With 14 3/32, 09 N 1/04 1986.

2. USSR author's certificate 1240790, MKI With 14 3/32, 1986.

3. USSR author's certificate 1442557, MKI With 14 3/32, 1998 (prototype).

4. Stiasny E. Tanning chemistry. Gisleham, M. - L., 1934, S. 94-95.

5. Chemistry and technology of leather./ Under. ed F. O'flaherty. Publishing house of scientific and technical literature of the RSFSR, M., 1960, T. 1, S. 363.

6. Stiasny E. Tanning chemistry. Gisleham, M. - L., 1934, S. 492.

7. Ibid, S. 189.

8. Chemistry and TX2">

1. How decamerone tannery wastes, including their serial processing in the alkaline electrolyte and acid-salt solution, washing with water, neutralization, repeated washing and dehydration, characterized in that the alkali-salt and acid-salt processing is carried out in two stages each in alkaline-saline treatment use solution composition, g/l: NaOH - 20-25; Na2SO4- 15-18; water to 1 l, and for acid-salt treatment use solution composition, g/l: H2SO4- 45-50; Na2SO4- 15-18; water up to 1 l

2. The method according to p. 1, characterized in that the first stage alkali-salt processing the working solution is prepared with caustic soda solution by adding sulfuric acid.

3. The method according to p. 1, characterized in that in the second stage alkali-salt processing using a spent solution of the first stage alkali-salt processing this batch, pre-adjusted to the content of NaOH 23-28 g/l, with the formation of a working solution of composition, g/l: NaOH - 20-25; Na2SO4- 15-18; water up to 1 l

4. The method according to p. 1, characterized in that the acid-salt waste processing on the first and second stages are the remaining parts from the PRS sulfuric acid with a concentration of 90-100 g/l prior to the formation of a working solution composition, g/l: H2SO4- 45-50; Na2SO4- 15-18; water up to 1 l

5. The method according to p. 1, characterized in that the first stage of the acid-salt processing subsequent batch use the spent solution of the second stage acid-salt processing the previous batch, pre-adjusted to the content of N2SO465-73 g/l, with the formation of a working solution of composition, g/l: H2SO4- 45-50; Na2SO4- 15-18; water to 1 L.

 

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