The environment situation of our country has become more and more rigorous. Using cement kiln to treat solid waste is a new way to solving this problem which is not only a new direction for cement industry but also attract more attention from the industries causing waste solid.
Senior professor of solid waste treating industry indicates that using the specific working condition of high temperature & long stay time of smoke during cement production and appropriate solid waste entering into calciner together with raw meal in a specific rate can directly be calcined to be cement clinker, cement kiln has good conditions for dirt treating and rubbish which supply a new selectable way for solid waste treatment of our country.
Since 90s of last century, our country has started to researched & promoted the technology using cement kiln to treating solid waste including Huaxin Cement, Hailuo Cement, Jinyu Group, Sinoma, etc. has started practical application meanwhile cement kiln assisting solid waste treatment has specific feasibility & superiority which has gained industrial approval. However, the actual promoting effect for years is not good. Via the statistics, since one 2000tpd cement clinker kiln is used for solid waste treatment in Beijing cement plant in 1998, it has been 15 years while there are only 20 lines which is only one line per year.
There are a lot of reasons for slow development of using cement kiln for solid waste treatment. First, technical reason: some of the current cement kiln treating solid waste project, some has complicated rubbish crushing & screening system, some has dependent sludge heat drying system which are advanced pre-treating system and makes rubbish and sludge be able to used as resources which is one of the important problem to be solved for solid waste treating industry.
2nd economic efficiency reason: as rubbish is not classified so it can not be used as resources, sludge has high moisture content and pipe network construction is not complete with high sand content & low organic matter which are decided by specific national condition of China and low quality of living rubbish & sludge.
While Zhou Guoqin think that the more important reason for slow development of using cement kiln for solid waste treatment is related to the acknowledge, self-development & location of cement industry .
Via introduction, our solid waste industry has over twenty or thirty year’s history, until now, technical level and market operating mode is very mature. For treatment of living rubbish, our country has complete law & rules, technical standard, construction operating rules, complete compensation rules. As new solid waste area, sludge treating technology has developed for over ten years, relevant rules is gradually completed, marketing mode is gradually becoming mature.
Before cement enterprise is repeating the old way of solid waste treating industry. Cement industry independently research without using the achievements of solid waste treating industry which waste abundant manpower & financial resource meanwhile it delay the market opportunity.
Cement kiln is used for solid waste treatment seems that it is action between cement production and solid waste treatment. Does this action mean that cement industry has one more competitor of solid waste treating enterprise?
The answer is obviously no. Cement enterprise should clearly know that: whatever helping to treat living rubbish, sludge or other rubbish, the final target of cement enterprise is to produce qualified cement product, its competitor is always cement enterprise, not solid waste treating industry.
Others, cement enterprises should pay more attention to following problems:
A. Capacity of cement production line limits the scale of solid waste treating capacity. Cement kiln capacity for treating solid waste should match the capacity of cement production line which can not enlarge the treating capacity without limits. The data from current solid waste treating project with cement kiln, the volume of solid waste without pre-treatment is about 3% while the volume of solid waste with pre-treatment is about 10-15%.
B. Pay more attention to living rubbish and sludge with high content of chlorine,
Sodium & potassium which may bring harm to cement quality. That is to say, the core of cement enterprise is to produce qualified cement, once the quality of cement is bad, its achievement is obvious.
C. During treatment of living rubbish and sludge, etc. solid waste, our country has serious exhausting control standard which is much higher than that is executed during cement production, if cement industry developed to treat solid waste in large scale, it may execute more environmental standard.
D. Adding living rubbish, sludge to produce cement may have specific risk.
As one product may comply with various standard, but consumer still can not accept it. For example fertilizer produced using living rubbish and sludge, its various index comply with quality requirements, but when consumer know living rubbish and sludge is added, sales is effected immediately, such condition has many example in domestic and foreign cases.
Comprehensive evaluation of the advantage, limits and possible elements of cement kiln for solid waste treatment, cement enterprise can consider treating some living rubbish and sludge via its condition, but it is better not to expend in large scale as if do like that, it may cause the opposite situation.
Cement production and solid waste is complete different area, now they are connected together causing possible cooperation. Now suggest cement industry should strengthen the cooperation & communication with solid waste industry, step into the way of socialized cooperation & professional production, integrate social resources, take industrial advantage and promote industrial, scientific & high efficient development.