Correct perception of abrasives
Correct perception of abrasives
First, cement enterprises to buy grinding aid to see the cost performance
Many cement enterprises are first to see the grinding aid offer, and then do the test, so that the excellent grinding aid blocked out of the enterprise. The main purpose of cement enterprises using grinding aids is to save energy and reduce consumption, improve the performance of cement, can not only look at the price, only the low purchase price as the winner. The amount of grinding aid brought into the cost is not a measure of the excellent standard of grinding aid, excellent evaluation of the effect of grinding aid is to bring the amount of economic benefits and cement performance improvement. Due to the lack of comprehensive communication, enterprise personnel individually consider the gatekeeper of their respective jobs and give too many definitions to the procurement and use effect of grinding aids, thus affecting the actual use effect of grinding aids in enterprises. In fact, the purchase of grinding aids should first do a large grinding production test, and then according to the actual test effect, cost performance, etc. to tender.
Second, the recommended amount of grinding aid admixture is a broad figure
Like other cement raw materials, grinding aids can be adjusted according to the physical properties of cement in the process of use, while the mill working conditions and raw material changes in the cement production process will affect the actual use of grinding aids. Therefore, in the process of using grinding aids in cement enterprises, the grinding aid admixture should be adjusted appropriately according to the grinding conditions, and the excellent benefits of using grinding aids should be obtained through tests. In the process of after-sales service, we have seen a cement enterprise mix our 5‱ grinding aid to 8‱, and communicate with its laboratory director and production leaders at that time, asking why the mixing amount is adjusted upward so much? It turns out that they are also based on the test results to make a judgment. Their mixed material limestone dosage is small, now the dosage is adjusted to 12%, but because the limestone open storage moisture changes, so in the use of the process to increase the amount of grinding aid doping, dosing adjusted to 8‱, table hour production than before 6 tons (5%), clinker used 3% less, the comprehensive economic benefits than the grinding aid to 5‱ The overall economic benefit is 3 yuan more than when the grinding aid is used to 5‱.
Another company, when producing 42.5 grade cement, added the recommended 3/‱ grinding aid at 2.7‱, and when producing 32.5R cement, the grinding aid was added at 3.2‱~3.5‱. The reason is that the mixture moisture in 42.5 cement ingredients is small and the material flow rate is fast, and the mixture moisture is slightly larger in the production of 32.5R cement, and the 32.5R cement requires a greater yield raising and enhancing effect, so they find these two blending amounts according to the actual situation, and it is more economical to use. Now many enterprises in the contract when the grinding aid dosing amount is fixed, good control of the grinding aid into the cost, limit the process director and the field operator's test adjustment space, quality control personnel according to the strict implementation of the limit is also easier to operate, but not necessarily produce economic use of the effect. Therefore, in the actual application of grinding aid, production control personnel should do more tests according to the production situation.
Third, the mill parameters need to be rebalanced after the overhaul
In March and April every year, there are often customers who reflect that the effect of grinding aid has become worse, the strength is not as high as before and other problems. At this time, most of these companies have replaced the liner plate and re-graded the steel balls. More often than not, the step liner is replaced in the first bin, the steel balls are re-graded in the second bin, the steel balls that are too small and irregular are picked up and re-graded, and the dust collector at the end of the mill is replaced with a filter bag, so the ventilation effect is better. Therefore, in the case of unchanged control index, it is easy to have a fast mill flow rate. Although the fineness and specific surface area control indexes are unchanged, the particle gradation of cement has changed, which affects the 3-day and 28-day strength of cement. In this case, it is recommended to do a particle gradation ratio of the finished product, and then change the particle gradation by adjusting the mill system parameters to achieve a new balance.
Fourth, the correct measurement of grinding aid effect
The existing liquid cement grinding aids are generally added at 0.2% to 0.02%, and the mainstream is added at 0.1% to 0.03%, the main effect is to improve production and enhance. Functional grinding aid can properly adjust the setting time, cement water demand, early and late strength, etc., but the total of these adjustments are basically limited, because the grinding aid is different from the concrete admixture, which accounts for 1% to 2% of the concrete cementitious material. The admixture amount of grinding aid in cement is relatively low, and the relatively low admixture amount makes it play various functions is very difficult to achieve. In the process of service, we have met customers who asked us to 4‱ of grinding aid, to ensure the original enhancement, the premise of raising the effect of the same period of condensation time extended 40 minutes, there are requirements to shorten the condensation time of more than 60 minutes. Like the setting time adjustment, in fact, the cement plant itself is relatively good adjustment, and as the adjustment of water demand requires grinding aids, mixed materials and mill parameters with the adjustment. Adjustment of cement and concrete admixture adaptability, simple or through the concrete ratio and concrete admixture to adjust.
There are also various problems that cement companies propose to solve through the adjustment of cement grinding aid. In fact, a good grinding aid formula, from research and development to formula finalization and then to market at least a year or more, there are technical reserves of the formula grafting and fine-tuning also need to verify through testing. Although many sales and service personnel of grinding aid enterprises to please cement customers, cement customers for the problems raised without thinking that all can be solved, and even some small grinding aid enterprises in order to win the favor, to win the eye, the opening is "we are the hospital of cement enterprises, there is no problem that can not be solved here", but the author believes that : for the problems raised by cement enterprises, can help solve, temporarily can not solve the consultation to discuss, but do not delay the cement enterprises themselves to solve the problem. As the sales volume is relatively large, more customers of the grinding aid enterprises, its technical service personnel to go more customers, encounter more problems, problem-solving ideas are more, so the cement enterprise customers want to rely on the grinding aid enterprises to solve problems. But to recognize the point, some problems are not mixed with 0.1% to 0.03% grinding aid can be easily solved.
These are more problems encountered in the market now, and I hope that it will help the sales and application of grinding aid enterprises to face the cement grinding aid and use it well.