【JST-042】One-on-one consultation office for chlor-alkali technology
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This post was last edited by Firefly on 2015-4-10 08:32. Technical discussant: rjs999. Specializations: salt chemicals, refining, fluorine chemistry, silicon chemistry, fertilizers, fine chemicals… My area of expertise is chemical technology management. Daily/weekly online time: 1–2 hours per day from Monday to Friday. Work experience: over 25 years
Why does 98% sulfuric acid turn slightly white after being stored in a tank for a long time?
Your question is too vague – is it the surface of the sulfuric acid that turns white, or is the entire sulfuric acid solution changing color and turning white, or is it the area where the storage tank’s shell comes into contact with the sulfuric acid that turns white?
98% acid may undergo changes over time when stored in a tank, and this is related to various factors such as the source of the sulfuric acid (the content and composition of impurities in it), as well as the material of the storage tank. Please describe the situation clearly on the second floor.
LZ, sorry to bother you, but could you give a brief overview of how to be a good middle-level manager? Or rather, how should middle-level managers behave for you to appreciate them?
Middle managers are the tier of managers who sit between frontline staff and senior executives, and their roles correspond to the functions of that level. Each position has its own characteristics, and the role of middle management is to act as a link between higher and lower levels. 1. Professional ethics ； 2. Professional skills ； 3. Understanding and communication ； 4. Judgment ； 5. Execution ability ； 6. Diligence and hard work. The points mentioned above are merely my personal opinions.
In the chemical industry, technology is a general discipline, which is primarily based on chemical unit operations that all stem from mass transfer, heat transfer, reaction, and separation.
Concentrated sulfuric acid with a low impurity content is very clear and essentially transparent; as mentioned earlier, it turns white after being stored for a long time, and the reason for this is the formation of contaminants during storage. For example, sulfuric acid obtained by drying chlorine gas with concentrated sulfuric acid is also white. A test was conducted, and it was found that the composition of the impurities had changed.
I would like to ask: how can one prevent re-clouding during pretreatment when the quality of raw salt is poor?
Due to the poor quality of the raw salt, its impurity content – particularly insoluble substances, as well as impurities such as calcium, magnesium, and sulfate – is bound to be much higher than that of the materials normally used. If the original pretreatment procedures are continued, there is a high risk of cross-contamination. To this end, the following measures are recommended: 1. Maintain stability in the quality of raw salt (this is the most direct measure; ensuring the quality of raw materials is the first step in guaranteeing the quality of factory-produced products), so as to prevent process fluctuations due to variations in raw materials ； 2. Increase the pretreatment time (increase the residence time) to allow impurities to mature and settle fully ； 3. Reduced production (to alleviate processing load) ； 4. Appropriately increase the concentration or amount of the sedimentation agent (determine the amount to be added based on the impurity content and the characteristics of the insoluble substances). 5. Adjust other process parameters (such as temperature, mixer speed, pumping flow rate, and the amount of various treatment chemicals added (BaCl2, soda ash, etc.).