KR880001253B1 - Preparation for alum - Google Patents

Abstract

High water-soluble alum powder is prepd. Thus, 65-75 pts. of satd. Al2(SO4)3.18H2O soln. is reacted with 15-20 pts. of satd. (NH4)2SO4 soln at 20-40≰C with adding 1-3 pts. of 10 w/v % ammonia water and agitating at 40 rpm, and then the sonl. re-reacted with 20 pts. Na2SO4 powder (70-250 mesh). The resulting ppt. is filtered, dehydrated, and air-dried for 8hr at 40≰C to give > 150mesh alum powder (yield, > 95%).

Description

Powder Alum Manufacturing Method

The present invention relates to a method for producing powder alum (ALUM), which is prepared in the form of fine powder of about 70-200 mesh directly at the time of manufacture, having a high solubility in water and a high dissolution rate, and a small amount of redeposition precipitation even in a low temperature aqueous solution. to be. Alum is a double salt of M ₁ MIII (SO ₄ ) ₂ 12 H ₂ O type made by sulfates of monovalent metal salts such as sulfuric aluminum, alkali metal, thallium and ammonium, crystallized into octahedron and mixed with each other. There is a characteristic. M ₁ is a monovalent metal such as Na, K, Rb, Cs, NH ₄ , T 1, and AIII is a trivalent metal such as AI, Ga, In, Ti, V, Cr, Mn, Fe, Rh, Lr.

Alum is generally known in the manufacturing process is a mixture of sulphate in the proportion shown in the chemical formula and heated to evaporate the moisture and crystallized in a fixed tank containing a large number of weights to induce crystals for a long time after the crystallization of agglomerate of a suitable size and alum If necessary, it was pulverized by a pulverizer and then screened by a screening netan pressure screener particle size has been used to make the powder of the desired particle size. However, the large crystal alum produced in this way is not only complicated in the manufacturing process but also added to the grinding and sorting process to make powder alum. Solubility in water is low, the dissolution rate is slow, and the water temperature decreases. Recrystallized and participated in the process of processing natural protein materials such as leather, wool fibers and silk fibers that are inconvenient to use due to recrystallization and participating in the treatment of pectin removal. There are many direct and indirect shortcomings such as the complexity, the increase of working cost and the deterioration of working environment.

The present invention is to prepare a powder alum by a new method through the course of several years of clinical trials for the purpose of correcting this drawback M ₁ , AI (SO ₄ ) ₂ · 12H ₂ O The temperature and specific gravity of M ₁ dissolved in the crystal water are compared.

As shown in the above table, it can be seen that sodium (Na) in the monovalent metal that binds to alum is dissolved at the lowest temperature. In addition, thallium (T1) is a large specific gravity, but rare and bulky amount of industrial use value and potassium (K) and ammonium (NH ₄ ) is valuable. In addition, the amount of water contained in alum plays a decisive role in proportion to the solubility in water.

As shown in the table above, sodium (Na) is much larger, followed by ammonium (NH ₄ ) and potassium (K).

In contrast, it can be seen that M ₁ should be sodium (Na) or ammonium (NH ₄ ) or potassium (K) to prepare alum with high solubility and high dissolution rate even at low temperatures.

On the other hand, depending on the temperature, it can be seen that only ammonium (NH ₄ ) is vaporized even at a temperature below 0-100 ° C.

The present invention is based on such a contrasting performance and can utilize its physical properties, while increasing the chemical function of the alum, while increasing the osmotic pressure to increase the efficiency of the work process, such as when the fiber material as described above is used as a blank material And to compare the solubility in water to manufacture a mixture of sodium sulfate (Na ₂ SO ₄ ) to improve the workability by the sulfur (S) component reinforcing action to verify the contrast effect is as follows.

As shown in the table above, the alum shows much higher solubility of sodium sulfate.

The present invention is to produce a powder alum of excellent performance by using the performance and physical properties according to the above contrast bar described in detail by the manufacturing process as follows.

Manufacture process

The first step to prepare an aqueous solution of aluminum sulfate and aluminum sulfate salt completely dissolved with stirring _{(AI 2 (SO 4) 3} , 18H 2 0- natural acid exhibited even equal to) the 20-30 minutes to put enough purified water about ₄₀ RPM aluminum sulfate Make an aqueous solution and leave it for 8-24 hours to cool the exotherm generated when making the aqueous solution below 50 ℃.

The solubility according to temperature in the aqueous solution of aluminum sulfate is as follows.

Solubility is the number of aluminum sulfate dissolved in 100 g of water.

Ammonium Sulfate Solution Preparation

(1) Ammonium sulfate (NH ₄ ) ₂ SO ₄ ) is sufficiently added to the purified water to make a solution at 40 ℃ or less. Above 40 ° C, ammonia is easily released, evaporates and becomes an acidic solution. The most ideal melting temperature is 20 ° C. The solubility of ammonium sulfate is 76.3 g / H ₂ O 100 g at 20 ° C.

(2) Prepare 10% of ammonia water separately.

Step 3: Preparation of Sodium Sulfate (Na ₂ SO ₄ ) Salt Powder Secretion Sodium Sulfate is anhydrous Na ₂ SO ₄ and 10 hydrochloride Na ₂ SO ₄ , 10H ₂ O, so 10 hydrochloride is 40 ℃ -100 ℃ Heat to remove water to make anhydrous salt and prepare it as fine powder of 70-250 mesh.

Fourth Step: Preparation of Powder Alum

(1) 65-75% of aluminum sulfate aqueous solution prepared in the first step under the temperature condition of 20-40 ℃ by using a stirring device and a cooling stirrer equipped with ammonia water from the bottom (solubility varies depending on temperature, but 36.2 based on 20 ℃) / H ₂ O 100g, the amount is added or decreased depending on the temperature) and 15-20% aqueous ammonium sulfate solution prepared in the second step (1) (Ammonia is released as the temperature rises, the amount is added and reduced, solubility 76.3 g / H ₂ O is 100g, so no aqueous solution is added) and the agitator is rotated at a rotational speed of 40 RPM to form a cross-linking reaction, resulting in precipitation crystallization of ammonium alum (NH ₄ AI (SO ₄ ) ₂ 12H ₂ O). As it is organic, it acts as a bubble in the aqueous solution, forming a foam state, and vaporization is lost. Therefore, large crystals of alum crystals are hindered and further hindered by stirring of the stirrer. Therefore, powder alum is made, but the following process is applied to increase productivity.

As the process of (2) (1) proceeds, ammonia is advantageous due to the increase in temperature, and the vaporization loss amount increases, so that the alum precipitation yield decreases, and an additional amount of ammonia water prepared in the second process (2) is supplied. .

으로 결합하여 미분상의 분말 명반이 석출된다. 이것을 공지의 여과포에 넣어 탈수기로 탈수하여 유리수분을 제거하면 70-150메쉬 입도의 분말 명반만을 수집하여 제품완료화 할 수 있으나 더욱 용해성이 좋고 저렴한 것을 생산하기 위해 다음 공정을 진행한다.(3) After about 20 minutes at which the alum deposition is completed, add sodium sulfate prepared in the third step in powder form, and stir for 5-10 minutes at a stirring speed of RPM ₄₀ . This alum decision number and conjugate

The fine powder powder alum is deposited. If this is put into a known filter cloth and dehydrated with a dehydrator to remove free moisture, only the alum of 70-150 mesh particle size can be collected to complete the product, but proceed to the next step to produce more soluble and cheaper.

(2) Sodium sulfate 20-30 prepared in the third step to 70-80% of the ammonium alum collected by putting the ammonium powder alum precipitated through the above 4 step (2) into a well-known filter cloth and dehydrated with a dehydrator to remove free moisture. If the mixture is added with% and left for 3 to 12 hours, sodium sulfate is highly hygroscopic, and thus absorbs the free water and crystallized water of the ammonium alum to form a conjugated state, thereby making a mixture. The product in this state has the same physical properties as the product in this step (1) but has a slightly lower rate of dissolution when used.

Fifth Step: Preparation of Ultrafine Alum

When the alum prepared in the 4th step is heated to 40 ° C or higher for 1-8 hours or left in a dry atmosphere, the moisture contained in the conjugated phase evaporates, the sodium sulfate is enriched, and the crystals are further decayed. You can make a differential command.

In the above manufacturing process, limiting the alum precipitation temperature to 20 ° C-40 ° C in the fourth step is not efficient due to the slow reaction rate below 20 ° C, and ammonia is favorably above 40 ° C. There is a drawback that the yield is lowered and the working condition is worsened by the smell of ammonia.

In addition, when too much ammonia occurs, aluminum oxide (AI ₂ O ₃ ) is precipitated to reduce the quality of the alum, which is to limit the precipitation work temperature between 20-40 ℃ to prevent this.

The present invention prepared in this way is a fine powder, solubility, large solubility, and acts on sodium sulfate containing Na metal fast even at low temperature to quickly melt the concentrated concentration to be a good alum solution, which is difficult to precipitate and precipitate at low temperatures. The dissolution facility can be omitted, and the osmotic pressure is large, which makes the use of all kinds of work more efficient. The ammonia solution is rich in ammonium (NH ₂ ). Cystine bonds during the fiber bond is also good bar is the effect of improving the fiber quality.

Therefore, the present invention is a very excellent invention that provides a large industrial use value, efficient and effective alum.

Examples of the present invention are as follows.

Example 1

(One). Aluminum sulfate was added to purified water and stirred for about 20 minutes at RPM ₄₀ to leave the completely dissolved solution for 18 hours to make an aqueous aluminum sulfate solution of 36.2% by concentration at 20 ° C.

(2). Separately, ammonium sulfate was dissolved in purified water at 20 ° C. to make a solution of 76.3% concentration at 20 ° C.

(3). Separately, prepare 10% aqueous ammonia.

(4). Sodium sulfate is made anhydrous and prepared as fine powder ground to 100 mesh.

(5). Agitate the agitator and keep the temperature of the cooling stirrer supplied with ammonia water at the bottom at 30 ° C, add 70% aqueous aluminum sulfate solution in (1), and rotate the stirring blade at RPM _40, and add the aqueous ammonium sulfate solution in (2). Add 15% and continue to stir for 20 minutes while continuing to react. As the temperature rises a little, ammonia gas is evolved in the form of foam in the solution. As a result, large crystals of alum are stopped and powder alum is precipitated. It becomes the thick solution of the state. The alum produced in this way has a low yield and therefore a high production terminal.

(6). In order to improve the merits, ammonia is released by exothermic reaction and in order to prevent alum precipitation from decreasing as vaporization is lost, add 1-3% of ammonia water in concentration (%) of paragraph (3) to continue the reaction to increase the precipitation yield of alum. As much as possible, the production cost is reduced.

(7). In the saturated aqueous solution of ammonium powder alum, 20% of sodium sulfate powder (4) is added and mixed for 10 minutes to improve solubility even at low water temperature of alum. To precipitate the powder alum completely.

(8). The powder alum made in (7) is used as it is, but the mixture is mixed with 80% of sodium sulfate powder and 20% of sodium sulfate powder for 8 hours, and left for 8 hours to be suitable for requesting high aqueous solution. Make a powder alum and use it as is.

(9). On the other hand, in order to make the alum made in (8) easier to dissolve and dissolve in water, the crystal alum is weathered and dried for 8 hours at 40 ℃ to make ultra fine alum.

The alum of the present invention prepared in this way is anhydrous salt of sodium sulfate is 10 hydrate, so the concentration of the aqueous solution increases and the alum solution dehydrated in solution at 20 ℃ during the manufacturing process can be recovered and used again the yield is more than 95% It will be. The production process of the present invention is applied to the production of powder alum, such as chromium alum, in addition to aluminum sulfate alum, and is widely used industrially in various industries such as pulp, paper, and textiles.

Claims (1)

In the preparation of alum, the mixing temperature of the aluminum sulfate solution and the ammonium sulfate solution is mixed and stirred between 20-40 ° C. to cause ammonia gas to be bubbled to form a foam. Soluble powder alum production method characterized by adding 20-40% of sodium sulfate while increasing the alum precipitation rate by adding about ammonia water.