Regarding the treatment of alkali slag
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Last week, I visited the Second Chemical Plant of Qilu Petrochemical to examine their systems for treating alkaline slag and VOC waste gases. These systems utilize genuine Korean Kepo biochemical technology. By comparing this with the wet oxidation method used by Jingbo Petrochemical for treating alkaline slag, as well as the biochemical treatment methods employed by Dongming Petrochemical, it was found that: 1. The wet oxidation technology used in China is not yet mature enough, and it does not achieve the desired results; even after treatment, the COD level remains very high, which causes problems for subsequent high-efficiency evaporation systems. Moreover, such wastewater cannot be discharged directly into sewage treatment plants； 2. The domestic biochemical technology sector is rather chaotic, with different companies having varying understandings of this technology. Most of them are unable to master the core techniques involved in strain cultivation, let alone the preparation of nutrient solutions. They can handle wastewater with high ammonia levels and high COD for a short period of time, but they cannot cope with such wastewater over an extended period. The alkali slag treatment system at Qilu Petrochemical’s Second Chemical Plant has been in operation for almost 10 years. Some technical upgrades were carried out during the early stages of its operation, presumably related to the recovery of phenols and other by-products. Other than that, the system has operated reliably, with no instances of excessive emissions or impacts on the wastewater treatment plant. There’s not much to say about VOCs – the smell is much better than it was in the 2000s. It seems that domestic technology still needs to work harder to catch up with that of the Koreans!
This post was last edited by ylb913 on 2016-12-20 at 19:43. I replied to this topic out of genuine concern – there are too many irregularities in China regarding the handling of alkali slag, waste acid, etc.; it’s absolutely common for people to make money by dumping such materials in some random ditch. To this day, our factory has not found any mature process that allows us to handle it on our own; we have to pay others to take it away. Of course, it is necessary to review the handling qualifications of the receiving entities, especially after the judicial interpretations issued by the Supreme People’s Court and the Supreme People’s Procuratorate. However, it is not ruled out that there may be deliveries through unqualified channels, or that some items are sold at high prices to meet inspection requirements while others are secretly delivered at lower costs.
Our company is Qingdao Kebaio, a joint venture in which Korean Kebaio holds a stake. What you mentioned are indeed many real phenomena that occur. When communicating with clients, the most common issue we encounter is that they say we know or have discussed this before, and that biochemical technology simply cannot handle it or that it is unstable. Because several companies in the country claim to possess the technology for treating alkaline slag through biochemical methods, presenting patents and proof of past achievements, but in reality the projects they carry out end up deceiving their clients. Our company, Korea Quick Honey, was founded by Park Yong-seok, who is also the current chairman. He originally worked at SK in South Korea as the head of the environmental department, where he invented this technology; later on, he established Korea Quick Treasure Company. Later, it entered China, and at that time it partnered with other companies to establish several businesses there. These partner companies believed they had mastered this technology, which led to its widespread adoption in China. However, it has been verified that these companies have not fully mastered it, which leads many customers to consider this technology unreliable. It is for this reason that Korea Fast Treasure established a joint venture in the domestic market later on, in order to prevent the leakage of technology and ensure the smooth operation of the project.
What is done with the alkaline slag after it has been processed by this unit at Qilu Petrochemical?
The water volume for this batch of alkali slag is 280 cubic meters per day; the COD of the incoming water is 280, and after treatment the COD is less than 500, after which it is sent to the main wastewater treatment facility.
I previously saw that the cost of treating alkaline slag wastewater using wet oxygen is between 200 and 300 yuan per ton. What is the operating cost for this wet oxygen treatment method mentioned by the original poster?
The amount of 200-300 yuan you mentioned is accurate, but there are still two issues with this technology: one is the high investment required; it is understood that the jbsh system involves an investment of 30 million yuan, and the other issue is that the COD level in the wastewater remains high.
What is the COD level after treatment? Also, if it isn’t treated, the wastewater treatment plant will have difficulty dealing with this substance; but can the wastewater treatment plant handle it once it has been treated?