Abstract: With the continuous development of industrial production technology in China, people pay more and more attention to various production methods of industrial granulated blast furnace slag. Granulated blast furnace slag is an important part of concrete and cement. In the process of producing granulated blast furnace slag, the practical application of concrete and cement is often considered to select the production process. As we all know, the combination of concrete is related to the important properties of concrete, such as viscosity and stability. Therefore, in the process of producing granulated blast furnace slag, the selection and application of grinding technology need to be combined with the application of various technologies. In this study, the basic characteristics of granulated blast furnace slag are briefly analyzed, and then the application of vertical grinding pre-grinding technology in the production of granulated blast furnace slag is explored in combination with practical production application.
Key words: granulated blast furnace slag; Vertical milling technology; App application
In recent years, more and more attention has been paid to the research on the production technology of granulated blast furnace slag. The technical level of blast furnace production directly affects the smelting level of the whole enterprise, and the implementation of technical means directly affects the production level of blast furnace. After the production level of blast furnace is affected, the slag produced is also affected. It is necessary to analyze the technical means in blast furnace production and actively do basic work such as blast furnace maintenance. At the same time, according to different blast furnace market environment and economic requirements, the correct and suitable grinding process should be selected to truly realize the high efficiency and high quality of vertical grinding to produce granulated blast furnace slag.
1 granulated blast furnace slag
With the continuous progress of social economy, granulated blast furnace slag is more and more widely used, and it has gradually become one of the important components in cement and concrete. Granulated blast furnace slag is made by melting silicate and aluminosilicate as main components and then quenching granulation when smelting pig iron in blast furnace. Granulated blast furnace slag has many advantages in application. Granulated blast furnace slag has high total activity, specific surface area of about 400 or more, low heat and low alkali. As a mineral admixture in concrete construction, it can replace cement in equal amount, reduce cost, improve quality, and more importantly, solve some technical problems such as high heat, high alkali and cracks in major engineering construction.
As an important component of cement and concrete, granulated blast furnace slag plays an important role in building construction. The production of granulated blast furnace slag has also become one of the focuses of attention. Some scholars believe that in the process of producing granulated blast furnace slag, when preparing concrete for powder materials, it will be considered that the increase of powder surface area may lead to the increase of water demand of cementitious materials, which will further affect the workability of concrete. At the same time, the production of granulated blast furnace slag began to involve many details, such as limiting the content of glass body. This is to prevent slag powder from being mixed with other industrial waste residues or a large number of inorganic salts during processing, which is harmful to the performance of cement and concrete.
Pre-grinding technology of vertical mill
Pre-grinding technology of vertical mill is mainly realized by vertical mill. In the vertical mill, the main structure is composed of separator, grinding roller device, grinding disc device, pressurizing device, reducer, motor and shell. Among them, the classifier is an important part to determine the fineness of grinding products, which is composed of speed regulating transmission device, rotor, guide vane, shell, coarse powder discharging cone bucket and air outlet, which is efficient and energy-saving. Grinding roller is the main part of grinding materials. It is installed on the curved arm of the mill and presses on the material of the grinding disc under the action of external force. Driven by the grinding disc, the grinding roller rotates accordingly, so that the materials are crushed and crushed.
Judging from the application of vertical grinding technology at present, although the vertical roller press has high productivity and low power consumption, its micro-grinding technology is not mature enough to meet the requirements of cement powder grinding fineness. This is because the specific surface area of cement is generally around 350, and some fine ones are around 380. Because of the low fineness, the strength of cement can not be exerted, the clinker ratio needs to be increased, and the cost of batching increases. The ball mill can meet the product requirements and is relatively stable. However, although vertical mill and roller press have high productivity and low power consumption, their micro-powder grinding technology is not mature enough to meet the requirements of cement powder grinding fineness, so there is basically no roller press and vertical mill for final grinding in China at present. The application of vertical grinding technology in granulated blast furnace slag production needs to be continuously improved.
Application of Vertical Mill Pre-grinding Technology in Granulated Blast Furnace Slag Production
The application of vertical pre-grinding technology in the production of granulated blast furnace slag is a very concerned issue in blast furnace smelting industry. The choice of technical means in the process of blast furnace smelting directly affects the final output and economic benefits, and is also an important point to realize the sustainable development of energy. The application of vertical grinding technology in granulated blast furnace slag production is not only a technical problem, but also a technical means to reflect more energy-saving and environmental protection awareness.
3. 1 working principle of producing granulated blast furnace slag by vertical mill pre-grinding technology
Usually, after the vertical toner machine is started, when the vertical pulverizer works normally, the motor drives the grinding disc to rotate through the reducer, and the material falls into the center of the grinding disc from the feed port through the air lock feeder, and at the same time, hot air enters the grinding disc from the air inlet. With the rotation of the grinding disc, the material moves to the edge of the grinding disc under the action of centrifugal force, and is crushed by the grinding roller when passing through the annular groove on the grinding disc. The crushed materials are picked up by the high-speed airflow of the wind ring at the edge of the grinding disc, and the large particles directly fall on the grinding disc and are crushed again. When the material in the airflow passes through the upper separator, the coarse powder falls from the cone bucket to the grinding disc under the action of the rotating rotor for re-grinding, and the qualified fine powder is ground together with the airflow and collected by the dust collector, which is the product. Materials containing moisture are dried during contact with hot air flow. By adjusting the temperature of hot air, the requirements of materials with different humidity can be met and the required product moisture can be achieved. In addition, the production of granulated blast furnace slag with different thickness can be realized by adjusting the separator.
3.2 Main features of vertical pre-grinding technology for producing granulated blast furnace slag
The main characteristics of producing granulated blast furnace slag by vertical grinding technology are: (1) low investment cost. To realize the vertical mill technology, the work involved in crushing, drying, grinding and grading transportation can be directly completed by the vertical mill, and the required investment is well controlled. (2) High grinding efficiency: the grinding roller is used to directly grind the ground material on the grinding disc, which has low energy consumption and high overall working efficiency, even saving energy by 30% ~ 40% compared with the same type of production process (such as ball milling production process); (3) The product quality is stable: in the process of producing granulated blast furnace slag, because the material stays in the mill for a short time, it is easy to detect and control the particle size and chemical composition of the product and reduce repeated grinding. In addition, most vertical mills are equipped with devices to prevent direct contact between roller sleeve and grinding disc bushing, thus avoiding destructive impact and violent vibration and further stabilizing product quality.
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