Abnormal phenomena and treatment methods in the acid hydrolysis process of ilmenite

Acidolysis success will affect the quality of the entire production process, safety, yield, it is a key step in the production of titanium white powder. While it responded very complicated, many variable factors, but can be summarized as follows: a quality titanium iron ore is a prerequisite for acid hydrolysis process; b. The reaction temperature and the gassing condition is a key to the success of acidolysis. c. The ratio of mineral acid to acid solution determines the process of acid hydrolysis and its process indicators; d. Sulfuric acid concentration and preheating temperature affect the whole process of reaction and ease of operation; e. Mature time is an important measure to improve acid hydrolysis rate f. The leaching temperature and concentration directly affect the stability of the titanium liquid quality.

The main abnormalities and treatment methods in the acid hydrolysis reaction process.

During the acid hydrolysis reaction, the material is flushed out of the acid solution tank. The main reasons for such accidents are: a. The proportion of mineral acid in the reaction is not appropriate; b. The concentration of sulfuric acid is too high or the preheating temperature of sulfuric acid is too high; c. The temperature of steam preheating is too high or the amount of condensed water in steam is too much; d. The content of Fe2O3 in the ore powder is too high; e. the fineness of the ore fine is too fine; f. the mineral powder contains oil, the water is too high or contains other organic impurities; g. the steam pressure suddenly rises, or the main reaction suddenly stops blowing .

Preventive measures against pan accidents:
a. The main methods to prevent and solve the ore powder before mining are: a. Check whether the perforated plate is clogged before each feeding, and the solid matter with large objects or large pieces should be removed in time and then fed; b. Afterwards, increase the amount of air blowing and avoid early hydrolysis during leaching; c. Add mineral powder under the agitation of compressed air, and place the ore powder not too close to the middle; d. Adjust the concentration of sulfuric acid, and find solid phase When the solid is not easy to be leached, the blowing speed should be increased to speed up the leaching speed, while the temperature and concentration are strictly controlled; e. The temperature is kept at 55~75 °C during leaching, and the temperature is too low to increase the steam slightly; f. Try not to use Ilmenite with too high silicon and aluminum content to avoid excessive colloidal substances in the reactants.

. B acidolysis reaction rate is too low, the following main reasons:. a mineral acid than inappropriate or excessively low reaction concentration of sulfuric acid; B ilmenite higher rutile content does not participate in the reaction; C leach time. Too short, or the temperature is too low, the concentration is too high, the leaching speed is slow; d. The main reaction is not intense, the reaction solid phase is poor in porosity, and the curing time is too short; e. The fineness of the mineral powder is coarse and fine, and the ore is fine. The powder has poor quality of colloidal substances, or the quality of the flocculant is poor.

There are five main measures for prevention and resolution: a. The ratio of mineral acid to sulfuric acid and sulfuric acid concentration and preheating temperature should be strictly controlled according to the quality of each batch of mineral powder; b. Do not use ilmenite with high rutile content; c. The leaching temperature should not be lower than 55 ° C, the total titanium concentration should not be too high when controlling the leaching, to ensure sufficient leaching time, to avoid the need to discharge in advance due to premature reduction of trivalent titanium; d. Fe2O3 content, adjust the ratio of mineral acid to acid, sulfuric acid concentration, preheating temperature, control the severity of the main reaction, not too fast, not too slow, increase the amount of gas after maturity to make the reactants porous; e. adjust the fine powder Degrees within the process indicators, if necessary, prolong the reaction and maturity. Try not to use high concentration (>95%) sulfuric acid, strictly control the preheating temperature of sulfuric acid according to the temperature; c. drain the condensed water in the steam before opening the steam, stop the steam heating immediately when the main reaction starts, keep it with compressed air Good agitation. d. Reduce the pre-heating temperature of sulfuric acid and the concentration of sulfuric acid in the reaction or use the mineral powder with low Fe2O3 content; e. Adjust the fineness of the crushing of the ore powder, pay more attention to the reaction when using the fine ore powder in the bag filter and the wall of the silo Temperature and concentration; f. Avoid oil, paper, hemp rope, sacks, plastic bags, etc. mixed into the mineral powder, the tide mineral powder should be used after drying. 2 The acid hydrolysis reaction is hydrolyzed early. The main reasons are: a. The leaching time is too long, the temperature is too high during leaching; b. The speed when adding water is too fast or too slow; c. The temperature of the solid phase is too high, and it is leached without cooling; d. The acidity of the material is too low; e. too much water is added during leaching, causing the total titanium concentration to be too low; f. The steam valve leaks during the leaching process, or the temperature is too high during the reduction.

The solution and prevention methods are as follows: a. The temperature during leaching is strictly prohibited to exceed 80 °C, and the steam cannot be opened too fast when preheating with steam. In the case of high temperature, defoamer (oleic acid amide, etc.) or open the exhaust gas treatment system to help dissipate heat; b. When adding water, take it first and then slow, then submerge the solid phase and then press a certain rate. Add water to dip. Large tanks can be filled with water at the same time, or add waste acid and then add water and small water; c. Use compressed air to blow the solid phase and then add water; d. Adjust the ratio of mineral to acid to make the F value of the reactants Keep within the specified range, and add waste acid during leaching to expand e. Reduce the amount of water added, often measure the density during the leaching process, keep abreast of the concentration changes, avoid the total titanium concentration is too low; f. Steam valve is best Install double valve and pressure gauge to prevent steam leakage; g. Avoid adding small water in case of excessive temperature to prevent hydrolysis of titanyl sulfate in small water due to high temperature; h. Reduce the content of metatitanic acid in waste acid Avoid using low concentrations of water that has been hydrolyzed early.

After the leaching is completed, there are still many solid phase residues in the tank: the main reasons are as follows: a. The compressed air distribution is uneven, there is a dead angle, or the pressure of the compressed air is too low, the ore powder is not uniformly stirred, and the solid phase is at this time. The pores of the material are smaller than the rigid plates; b. The porosity of the solid phase is poor, or early hydrolysis has occurred, when the solid phase has a pale yellow color; c. The concentration of sulfuric acid is too high or too low (the solid phase is black or grayish white), steam If the preheating temperature is too low, the reaction will be mild, or condensed water will be returned to the tank; d. The maturity time is too long, and the temperature of the solid phase is too low; e. There is a tank of unreacted solid phase in the tank, which will accumulate in the future. More; f. The quality of the ore powder is poor, and there are more colloidal substances in the titanium liquid.

Pull studs are an important link between machine and tool.The requirements concerning accuracy,rigidity and reliability are very high.
Pull studs of minor quality not only decrease the performance of the machine,they are even a safety risk.
A breaking Pull Stud might cause severe damage on machine and workpiece and even injuries on persons.
1, Material: 20CrMnTi
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3, the type: Bt Pull Stud, SK pull stud, ISO7388 Pull stud, CAT pull stud, Mazak Pull Stud, MTB Pull Stud, NT pull stud
4, hardness: 56-60HRC
5, Surface blackening, grinding

DIN69872 Pull Stud Bolt

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