Some questions about calcium carbide acetylene

If it occurs in a dry state, then an α value is involved, which is the water ratio, or mass ratio

Reply to 2# Qilu Salt Chemicals: Hehe, I see. Thank you. I’d like to ask again: the calcium carbide slag that remains after dry-process acetylene production is said to be usable for making quicklime, which can then be used to produce calcium carbide once more. There are two steps in this process – drying and calcination – so isn’t a lot of water produced during these steps? What is this water usually used for in industry? Also, what is the purity of the resulting CaO? Is most of it unreacted slaked lime? Hehe, so many questions! Thank you again to 2# Qilu Salt Chemicals for your attention

Calcium carbide: the water-to-material ratio is 1:1.24; this is the mass ratio of the feed materials, with an excess of water taken into account to enable the water vapor and acetylene to be carried out of the reactor together.

One is the reaction; meanwhile, it is also necessary to cool it down

The moisture content of calcium carbide slag produced by dry methods is generally around 10%; this varies from one factory to another, with some factories managing it at 5%. As for the purity of the CaO obtained through calcination, it is still determined by the quality of the calcium carbide used!

I have been in this industry for almost ten years. The chemical name for calcium carbide is calcium carbide itself, and it is produced from CaO and coke in a calcium carbide furnace. Calcium carbide undergoes a chemical reaction with water to produce acetylene. The reaction is as follows: CaC2 + 2H2O = Ca(OH)2 + C2H2. The hydrolysis rate of calcium carbide refers to the proportion of calcium carbide that participates in this chemical reaction, out of the total amount of calcium carbide used. A hydrolysis rate of 99.93% means that out of every 100 parts of calcium carbide used, 99.93 parts participate in the reaction, while 0.07 parts remain unreacted. We generally don’t talk about the hydrolysis rate, but rather the acetylene yield. It is the ratio of the actual amount of acetylene obtained to the amount of acetylene that should be obtained based on the complete reaction of calcium carbide with electricity. This ratio takes into account not only the factor of calcium carbide that has not undergone hydrolysis, but also factors such as acetylene displacement and its dissolution in water, providing a more comprehensive view. There are two methods for producing acetylene from calcium carbide: one is called the wet acetylene process, and the other is called the dry acetylene process. 1. The wet acetylene process is a technology that was introduced from Japan in the 1970s; subsequently, the Ministry of Chemical Industry organized efforts to master and adapt this technology, resulting in the construction of 13 vinylon factories across the country at that time, all of which used the wet acetylene process. Simply put, wet-process acetylene is produced by intermittently adding calcium carbide to water to cause its hydrolysis. Due to the need for nitrogen purging of the upper and lower storage hoppers during feeding, as well as the presence of acetylene dissolved in water, there is significant waste. For our company, after numerous attempts, the best yield for acetylene is around 91%. 2. Dry-process acetylene is a new type of calcium carbide-acetylene process that has been developed in recent years. It was first put into production in Shandong; our company is the second dry-acetylene enterprise in the country. Dry acetylene, simply put, is achieved by adding an appropriate amount of water to calcium carbide. It can feed material in a uniform and continuous manner, and adjust the water addition ratio using the DCS system based on the moisture content of the dry slag. Since no displacement is required and there is no loss of acetylene due to dissolution, the yield is very high. Our company achieves an acetylene recovery rate of over 99% for this process. To ensure complete hydrolysis, our experience shows that the moisture content of the dry residue should generally be kept at around 2%. If you have any further questions, feel free to reach out to me.

It is feasible to reuse calcium carbide slag to produce lime, which can then be used as a raw material for calcium carbide, but the addition amount should not exceed 40%. Otherwise, the impurities in calcium carbide will re-aggregate, affecting its quality

Okman, I work with dry-process acetylene as well, but I’m a beginner. I really would like to exchange ideas with you regarding dry-process acetylene, as well as topics such as crushing, dust removal, and the use of calcium carbide slag. But how can I get in touch with you?