PVC pipe is extruded by hot pressing method after the cooperation of PVC resin, stabilizer and lubricant. It is the earliest plastic pipe developed and applied.
PVC-U pipe has strong corrosion resistance, easy adhesion, low price and hard texture. However, due to the leakage of PVC-U monomer and additives, it is only suitable for water supply system with transmission temperature not exceeding 45 ℃. Plastic pipes are used for drainage, wastewater, chemicals, heating and cooling fluids, food, ultra pure liquids, mud, gas, compressed air and vacuum system applications.
PVC pipe fittings include direct connection, tee and cross joint, and the tee is divided into 45 degrees and 90 degrees.
Advantages of PVC pipe PVC chemical pipe, PVC pipe fittings, PVC tube fitting, PVC hose, PVC pipe, PVC hose fitting Glove Industry Co.,Ltd. , https://www.gloveind.com
1. It has good tensile and compressive strength, but its flexibility is not as good as other plastic pipes.
2. Small fluid resistance: the pipe wall of PVC-U pipe is very smooth and has little resistance to fluid. Its roughness coefficient is only 0.009. Its water transmission capacity can be 20% higher than that of cast iron pipe with the same pipe diameter and 40% higher than that of concrete pipe.
3. Excellent corrosion resistance and drug resistance: PVC-U pipe has excellent acid, alkali and corrosion resistance, is not affected by moisture and soil pH, and does not need any anti-corrosion treatment during pipe laying.
4. Good water tightness: the installation of PVC-U pipe has good water tightness whether it is connected by bonding or rubber ring.
5. Anti bite: PVC-U pipe is not a nutrient source, so it will not be eroded by rodents. According to the experiment conducted by the National Health Foundation in Michigan, mice will not bite PVC-U pipes.
6. Performance test: curing time shrinkage splitting strength tensile property peel strength thermal stability application period storage period release of harmful substances.
Overview of recovery of gold and silver from silver-zinc shells
Silver zinc can lead Fire refining is an intermediate product in addition to silver and zinc. The factory that produces bismuth also adds zinc and silver to produce silver-zinc shells during the refining process.
Zinc has a strong affinity for gold and silver. When refined lead or refining bismuth, metal zinc powder is added to molten lead (or bismuth) solution, and gold and silver contained in crude lead (or coarse bismuth) are easily combined with zinc to form A zinc-silver-gold alloy that is small in density and insoluble in lead (or bismuth) liquid floats on the surface of the metal. This scum is called a silver-zinc shell. The silver content in crude lead or crude is 10 times higher than the gold content. The affinity of zinc to gold is greater than that of silver. The gold enters the silver-zinc shell first, so the silver-zinc shell also contains gold.
Commonly used in the distillation and zinc removal process to extract gold and silver from silver-zinc shells, some plants use some new processes.
This paper mainly includes four parts. 1. Recovering gold from silver-zinc shell by distillation and zinc removal method; 2. Removal of lead and layered precipitation enrichment and electrolysis of carnallite by silver-zinc shell; 3. Lead-rich ash blowing Law; 4, lead poisoning protection and treatment. Please refer to the relevant title of this website for details of each part.