Kong Xiangzhong: The essential attribute of returning cement grinding aid product quality

Abstract: Cement grinding aid is a good product that is conducive to energy saving in grinding and helps to improve the particle properties (wearability, dispersibility, improvement of material layer pulverization conditions, etc.) of the material to be ground. For a long time, cement grinding aids have been promoted and applied in cement production, and have achieved good energy-saving and emission-reducing effects. However, in the marketing and promotion of grinding aid products, I believe that there are some “misleading” tendencies that have helped Under the pursuit of different interests, the grinding agent production and operation parties and the cement enterprise users have some deviations in the understanding of the essential properties of the grinding aid product quality.

Kong Xiangzhong, Executive Vice President of China Cement Association

Cement grinding aid is a good product that is conducive to energy saving in grinding and helps to improve the particle properties (wearability, dispersibility, improvement of material layer pulverization conditions, etc.) of the material to be ground. For a long time, cement grinding aids have been promoted and applied in cement production, and have achieved good energy-saving and emission-reducing effects. However, in the marketing and promotion of grinding aid products, I believe that there are some “misleading” tendencies that have helped Under the pursuit of different interests, the grinding agent production and operation parties and the cement enterprise users have some deviations in the understanding of the essential properties of the grinding aid product quality. For example, the focus of the use of grinding aids is one-sidedly placed on the functional aspects of “reducing the amount of clinker, increasing the amount of mixed materials” and “increasing the early strength of cement for three days”. In the marketing propaganda, due to excessively amplifying the “enhancement” function of the grinding aid, neglecting the intrinsic quality of the grinding aid product itself, and even reflecting the “enhancement” function, the “false” phenomenon sometimes occurs, which makes some large cement enterprises use it. Grinding aids have doubts; in addition, the grinding aid enterprises are generally small in scale, and there are often unfair "low-price competitions" in marketing, which leads to a difficult market for good products.

What is the essential attribute of the quality of cement grinding aid products? I personally think: "On the basis of ensuring the quality of cement products, it is conducive to the improvement of the efficiency of the grinding system in the cement production process and the proper improvement of the performance of cement products. It is the essential attribute of the quality of grinding aid products." The market for agent products is not based on fair competition for quality and price pricing, but rather a high level of “accessibility” for amplifying product applications. This is the inversion of the essential attributes of the quality of grinding aid products. I feel that in the long run, the grinding aid products will lose the core competitiveness of “grinding energy saving”, and the scale of grinding aid enterprises will be difficult to become bigger and stronger.

The market competition of grinding aid products must return to the essential attributes of product quality, embark on the function of desalination, and emphasize the return of energy conservation, so as to lay the foundation for establishing a fair competition market environment, for the innovation development of enterprises and the structure of the industry. Adjustment brings opportunities.

First, improve product quality to upgrade product value

The cement grinding aid in GB/T 2678-2011 "Cement Grinding Agent Standard" is defined as: "Admixture added to the grinding effect of cement grinding without impairing human health and cement concrete performance." Careful implementation of standards, ensuring product quality, locking grinding performance, and returning to the essential attributes of product quality are prerequisites for enhancing the value of grinding aid products.

1, grinding effect. In the standard, the dispersion property of the cement grinding aid to the particulate matter is the main index for evaluating the quality of the grinding aid product. The dispersibility here should refer to the physical dispersibility (the dispersibility evaluation of the open circuit mill and the closed circuit mill is different). The dispersibility evaluation given in the standard has only two indicators: “the cement 45 μm sieve residue is reduced by not less than 2%, or the specific surface area is increased by not less than 10 m 2 /kg”. Due to the increased dispersibility of the material to be ground, the production of the grinding system is improved, the energy consumption per unit product is reduced, and the product performance is improved. It can be seen that the dispersion performance of the grinding aid (ie, the sieve residue and the specific surface area) is the only index to evaluate the effect of the grinding aid product, while the latter"s output, energy consumption and reinforcement index are mainly uncertainties caused by the dispersion. The side effect.

2, the impact on the performance of cement: especially in Table 1.2 of the standard 4.2 "grinding agent before and after the addition of cement performance indicators", the chloride limit in the cement before and after the addition of grinding aid gives a strict limit is "absolute The value is increased by no more than 0.01%", the test is the same cement sample, here the "0.01% absolute value" increase, it can be understood that the grinding aid product is brought in. GB175-2007 "general Portland cement" standard for the chloride ion content of cement is ≤ 0.06%, that is to say, the chloride ion content in the grinding aid exceeds the standard may cause the cement product to fail. When over-emphasizing the reinforcing function of grinding aids on cement, especially early strength, we often see some companies add a certain amount of industrial salt, including chloride and alkali metal salts, as an activator in the grinding aid production process. It will have a significant effect on the increase of early strength of cement. However, when the amount is too large, especially in the powder grinding aid, there are a large amount of salt components, which will bring about the performance of concrete, especially durability and late strength development. Serious quality problems. Therefore, strict control of the chloride ion content of the grinding aid is an important indicator of product quality, which reflects the safety of the grinding aid product.

Strictly follow the "Cement Grinding Agent Standard" to control the production process to ensure the quality and safety of the grinding aid product, and the energy-saving effect of the product is obvious. It is the most basic law-abiding and compliance requirement of the enterprise. Cement product quality standards require a percentage of the lily rate, and the quality of the grinding aid product serving cement should also require a percentage of the lily rate. Only by improving the product quality can the product value be upgraded.

Second, the cement grinding aid is not a cement enhancer

1. The mineral composition and mineral form of cement clinker mainly determine the strength of cement. The cement particle gradation and admixture varieties have an important impact on the performance of cement products. The "Technical Requirements" of "Cement Grinding Agent Standard" does not require the grinding aid to increase the early strength index of cement, and the improvement of cement early strength index as the evaluation index of the grinding aid product procurement contract will be the grinding aid. Product quality control brings false induction. It is one thing to study the reinforcement mechanism of cement grinding aids, but the traditional thinking of enhancing functions as the focus of product marketing seems to be changing. Although some organic alcohol amines have a certain promoting effect on cement hydration, the strengthening mechanism is more complicated, and there are individualized differences due to material changes and experimental errors. At least this kind of enhancement mechanism research is still not very good. This functional relationship of strength enhancement is described quantitatively.

2, some of the customer"s requirements are often traps, is also a trap for the grinding industry companies to design for themselves. Assuring and improving the strength of cement products is the responsibility of the quality control of cement plants. It is not possible to use partial aids to ensure partial guarantee. In order to obtain contract orders, many of our cement grinding aid companies have made a "courageous" commitment to deviate from the essential attributes of the quality of grinding aid products, which has harmed themselves and cement enterprises. In order to ensure the improvement of cement strength index, some grinding aid enterprises have added "chemical activators" which should not be mixed in the products to increase the early strength of cement, but this will bring safety to the quality of cement products using grinding aids. Hidden dangers.

3, no help to help the backward cement production capacity. It is precisely because of the overemphasis that grinding aids can improve the early strength of cement, which causes cement companies using grinding aids to produce bold and super-mixed mixed materials in low-grade grade cement, especially many medium and small cement grinding. In order to reduce the clinker ratio and reduce the production cost, the use of grinding aids is a “winning magic weapon” to ensure the low-grade cement strength, which leads to many small cement grinding station products (especially 32.5 grade cement). The chloride ion content is generally exceeding the standard, and even a large amount of alkali metal salts are added, which improves the early strength of the cement and the strength of the late strength is weak or even decreased.

4. Is personalized service or standardized service? Almost all grinding aid companies are taking a differentiated competitive business model that increases the value of after-sales service, and meets the needs of each mill and every cement product as much as possible. Each of the products corresponding to the standard can provide personalized service grinding aid products, so that cement companies often have no research and comparison in product bidding, most of them can only use the lowest price trial and error way to choose the bidding finalist, and the high quality and high price The grinding aid product may not be able to win the bid. I don"t object to product customization to meet the specific needs of customers. However, the service of grinding aid products is all cement companies with the same commonality. It is best to let cement companies have several grinding aid products such as A, B and C. To choose, instead of 10 companies to promote more than 10 different proportions of grinding aid products. Like the clothing industry, do we want to develop garment factories or develop tailors? It may be a misunderstanding to make all the grinding aid products into personalized products. It is the mainstream consciousness of pushing the ideal personalized personality into the market, perhaps the industrialization and scale development of the grinding aid industry for many years. The reason for the lag. There is a huge market for the demand for grinding aids, and why have our grinding aid companies been so hard and so hard for so many years? Should you reflect on yourself?

Third, relying on product standard innovation to guide market demand, relying on corporate brand building to lead the industry development

The market is built by the manufacturers, operators and consumers of the products. The role of operators in the market is to guide the correct positive consumption and drive the continuous innovation of product manufacturing, and to form a continuous escalation of consumption and innovation. It is imperative to create a market environment where the grinding aid products are fair and competitive. It is difficult to compare the quality of each grinding aid product horizontally, and establish a serialization standard of grinding aids with product quality as the core, so that cement enterprise users can choose to use it as a grinding aid in the standardization and serialization of products. It is the focus of innovation in the grinding aid industry. Returning to the standard to talk about quality, to solve the common problems of the components of the grinding aid product, stable and harmless, and to standardize the bidding evaluation standards of the product market, is the essence of the industry development.

Now, grinding aid companies have their own industry self-regulatory organizations, laying the foundation for coordinating the market and safeguarding rights. While strengthening market competition, we must promote the improvement of production concentration, optimize the allocation of resources, expand the scale of grinding aid enterprises, and create a brand of cement grinding aids in China.

Leaders of grinding aid enterprises must enhance product quality awareness, change traditional thinking methods, reposition the development model of grinding aid industry, improve research and development platform, improve research and development capabilities and level, and provide safe, reliable and efficient grinding for cement production enterprises. Agent products. Based on product quality, integrity management, and quality service, we can achieve enterprise profit growth. Business leaders also need to have a sense of social responsibility and have a correct sense of values and mission for the development of the industry in order to achieve healthy, stable and sustainable development of the grinding aid industry.

Acknowledgement: well-known grinding experts in the cement industry, chief engineer of Hefei Cement Research and Design Institute Bao Zheng, Professor Chen Shaolong from Jinan University, Professor Liu Futian, expert in cement grinding aid industry, general manager of Beijing Renzhong Technology Co., Ltd. Zhang Zaihong, former "Cement" magazine The editor-in-chief, Gu Zhiling, proposed amendments for this article.