Tar chemical test questions

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Tar workshop job training test questions 1. Responsibilities of this job. answer ； (1) Actively participate in production management and conscientiously implement operating procedures and safety regulations. (2) Responsible for the use, maintenance and upkeep of tools and fire-fighting equipment in this position. (3) Do a good job in the maintenance and upkeep of the equipment in this position and ensure safe production. (4) Take samples for testing in a timely manner and conduct accurate testing to guide production. (5) Responsible for various tests of products in the washing section. (6) Sampling tools should be kept clean, dry, used for specific purposes, and washed after use. (7) Responsible for adding samples for testing and submitting samples in a timely manner. (8) Responsible for the environmental sanitation of this position. (9) Fill in the operation record of this position carefully and keep it complete and clean. 2. Safety operating procedures for this position. answer: (1) Each laboratory technician is required to have a full understanding of the performance of the instruments and equipment used, and a sufficient understanding of the dangers encountered during the work process, so that various measures can be taken to prevent accidents. (2) Laboratory personnel must perform standardized operations and have a serious work attitude. (3) Fighting and shouting are strictly prohibited in the laboratory ； After working, wash your hands immediately. (4) Water, power, and fire sources have been used and must be turned off immediately. (5) It is absolutely not allowed to mix various chemicals at will to avoid accidents. (6) All experiments that produce pungent odors or toxic gases must be conducted in a fume hood. (7) Toxic and harmful chemicals must be kept by dedicated personnel. (8) When performing heating operations or flammable operations, the operator is not allowed to leave the experimental bench. (9) Fire-fighting equipment must be equipped in laboratories and warehouses, and laboratory personnel must be familiar with the use of fire-fighting equipment and fire-fighting objects. 3. Fill in the blanks: (1) The temperature of glycerol or glycerol aqueous solution used to determine the softening point of asphalt should not exceed 35°C. (2) When determining the asphalt softening point, the heating rate should be maintained at 5+0.2°C per minute. (3) When doing the naphthalene oil process, the flow rate should be controlled at 4---5 ml per minute. (4) When preparing dilute sulfuric acid with concentrated sulfuric acid, slowly add the concentrated sulfuric acid into distilled water and stir continuously with a glass rod. (5) The technical indicators of industrial naphthalene in our workshop comply with the secondary standards in GB/T6700-86. The crystallization point is not less than 77.5°C, the non-volatile matter is not more than 0.06%, and the ash content is not more than 0.02%. (6) The density of coal tar in YB/T 5075---93 (20℃), the g/cm3 requirement is: No. 1 coal tar 1.15---1.21 ； No. 2 coal tar 1.13---1.22. 4. Relevant contents of the two system documents. 5. “Details determine success or failure”, no excuses” are the basic concepts of the two books. 2. Defense questions: 1. Determination method of naphthalene content in wash oil. answer: Key points of method: When a crystalline substance changes from liquid to solid, it releases heat of fusion, causing the dropped temperature to rise significantly. When the rising temperature reaches the highest point, it is the crystallization point. Then based on the linear relationship between the crystallization point of naphthalene and its purity, the percentage of naphthalene in the sample can be calculated. Instruments used: Naphthalene crystallization point tester, molten naphthalene test tube, thermometer, beaker, water bath, tray balance. Reagents used: Naphthalene (chemically pure), sodium chloride (anhydrous after burning) Test procedures: (1) Pour the sample into a beaker, add sodium chloride to dehydrate it, weigh 5 grams of the sample into a test tube, add 20 grams of pure naphthalene (all weighed accurately to 0.1 grams), close the lid, and melt in a water bath at 85---90°C. (2) After the sample melts, add 2 grams of anhydrous sodium chloride, stir, let stand, and dehydrate. (3) When the sample is free of turbidity, quickly pour it into three-quarters of the height of the naphthalene crystallization point tester that has been preheated to 85°C, and immediately plug it tightly with a cork equipped with a thermometer (the thermometer is preheated to 80--85°C). The thermometer is inserted 20 mm away from the bottom of the crystallization point measurement. (4) Shake the crystallizer, the temperature will gradually drop, and observe the temperature at any time. When the temperature rises and reaches the highest point and stays for a period of time, the temperature is the crystallization point. (5) Read the crystallization point and check the corresponding table to find the naphthalene content of the wash oil at that temperature. 2. Determination method of tar moisture. answer: Instruments used: Distilling flask (500 ml), cooling tube (inner tube length 300 mm, outer tube length 250 mm), receiver (10 ml), gas lamp, tray balance (0.2 g sensitivity), measuring cylinder (volume 50 ml). Reagents used: Anhydrous toluene analysis steps: (1) Weigh 100 grams of the mixed sample at room temperature (weigh accurately to 0.2 grams), measure 50 ml of toluene, place it in a clean, dry distillation bottle, and shake carefully. (2) Connect the distillation bottle, receiver and cooling pipe. Plug the upper end of the cooling tube with some absorbent cotton to prevent moisture in the air from condensing inside the cooling tube. (3) Heat and boil so that the condensate drips from the end of the cooling tube at a rate of 2-5 drops per second. When the moisture in the receiver no longer increases, increase the flame and heat for a few minutes to stop distillation. (4) When the temperature of the liquid in the receiving tube reaches room temperature, read the volume of the water layer. If the water in the receiving tube is turbid, put the receiving tube into warm water to clarify it, and then cool it to room temperature for reading. calculate: The moisture content (WF)% of the sample is calculated according to the following formula: WF =V/GX100 where: V----The volume of water in the receiving tube, milliliters. G-----Sample weight, grams. Things to note: (1) It is easy to explode during the distillation process. Generally, two grains of zeolite are added. (2) All connections of the instrument must be tight. (3) When distilling, turn on the cooling water first and then ignite, and check the flow of cooling water frequently to prevent toluene from escaping when the water is cut off and causing a fire.