ANALYSIS OF THE RESULTS OF MODELING IN THE LVM FLOW PROGRAM IN OBTAINING CASTINGS OF INDUSTRIAL MILLS ARMORED PLATES

ABSTRACT

An improved version of ball mill casting linings is being developed using modern software. As part of the LVM Flow program, a 3D model of existing ball mill linings was developed. The casting defects obtained during the casting of the model were studied using the LVM Flow software. The causes of the formation of defects and the consequences that these defects can lead to are analyzed. By analyzing ways to eliminate defects identified with the help of modern technologies, information is reflected on ways to eliminate defects that may occur in the future. Design drawings of the middle and outer linings of ball mills have been developed, and through their analysis, the shortcomings of existing technologies have been identified.

АННОТАЦИЯ

Разрабатывается усовершенствованный вариант литейных футеровок шаровой мельницы с помощью современного программного обеспечения. В рамках программы LVM Flow была разработана 3D-модель существующих футеровок шаровых мельниц. Дефекты отливки, полученные при отливке модели, изучались с помощью программного обеспечения LVM Flow. Проанализированы причины образования дефектов и последствия, к которым могут привести эти дефекты. Путем анализа путей устранения дефектов, выявленных с помощью современных технологий, отражается информация о путях устранения дефектов, которые могут возникнуть в будущем. Разработаны конструктивные чертежи средних и наружных футеровок шаровых мельниц, и путем их анализа выявлены недостатки существующих технологий.

Keywords: 110Г13Л (Gadfield steel), Compass –3D software, SAE LVM FLOW, Niyami criterion (Ny), ball mill, metal waste, ball mill armor.

Ключевые слова: 110Г13Л (сталь Gadfield), программное обеспечение Compass –3D, SAE LVM FLOW, критерий Ниями (Нy), шаровая мельница, металлические отходы, броня шаровой мельницы.

It is known that the most commonly used mills in industry are ball mills. They are widely used in cement production. A considerable sum is spent on the futirovka of the mill. Extension of the service life of fuses - leads to an increase in the efficiency of the enterprise. it is possible to extend the service life of the fuses by reducing their defects when taking fuses by the method of casting. and improving the casting process with the help of modern computer programs will help reduce spending and increase efficiency. The purpose of this article is also to eliminate the above problems.

The development of technological processes for casting industrial mill armor plates is carried out not only for the purpose of producing high-quality castings, but also taking into account the economic feasibility of materials and current costs. This also applies to the extraction of castings from high manganese steel 110Г13Л (Gadfield steel). These steel castings are used in critical parts of the mechanisms under heavy-duty and abrasive conditions [1].

110Г13Л is preferred when choosing the material of the casting parts of the grinding and grinding equipment due to the properties of surface grinding as a result of external impact of steel. Subject to certain conditions that must be taken into account when developing the technological processes of casting, the high operational properties of this steel can be achieved. Gadfield is marked by an increase in the operational characteristics of steel castings and the requirements for Mill armor, in particular, leading to significant economic losses in the event of equipment failure [2, 3].

Therefore, the development and implementation of the casting process, including the design of rational casting systems that improve the quality of the casting and ensure the saving of material, while eliminating the formation of defects of the casting that worsen the operational properties of the casting, is an urgent task of the casting industry.

Currently, a huge number of casting factories and small enterprises are using modern types of programming. The use of fuses created using modern programs has high efficiency. One such program is the LVM streaming program. It is also advisable to use this program when casting industrial mill armor [4, 5].

A three-dimensional model of the casting was made to model the process of casting and crystallization of industrial mill Armour. Solid-state modeling software was chosen as Compass –3D software.

The calculated weight of the created three-dimensional model almost coincided with the actual weight of the armor. On the first attempt, the weight of the cast was measured, which in practice corresponds to the weight indicated in the drawing.

At the next stage of work, computer modeling of the process of casting and crystallization in the studied casting mold began. For this purpose, the modern specialized licensed SAE LVM FLOW program was used.

This program makes it possible to model the hydrodynamic and thermophysical processes that occur in the casting mold during the casting, crystallization and cooling in it. One of the most important advantages of using this program is that it allows you to assess its effectiveness at the stage of developing casting technology, compare various technology options, identify possible casting defects and make adjustments to eliminate them.

Color coding is used in this application to transfer information about modeling results to the user. The LVM Flow program we use to assess the quality of the crystallizing metal includes a dimensionless Niyami criterion (Ny) that takes into account local thermal conditions, alloy crystallization properties and conditions. It is used to predict porosity, the appearance of which depends on the feeding of the two-phase zone.

Because the casting of industrial mill armor, which is being cast according to existing technology, does not use modern software first, drawings of armor and a 3D drawing will be needed.

a)

b)

Figure 1. Drawings of ball mill armor used for cement production

a) ball mill external armor plotter b) ball mill medium armor plotter.

When the drawings were determined to meet all standard requirements the 3D drawing was modeled in a 3D Compass program.

a)                                                        b)

Figure 2. 3D models of ball mill armor

a) ball mill external armor plotter b) ball mill medium armor plotter.

When modeling the processes of crystallization and cooling of the ball mill armor casting in the mold, the conditions and parameters below were established:

- mold casting alloy brand 110Г13Л;

- the temperature of the pouring metal is 1470 °C ;

- mold material-sand-clay mixture

- ambient temperature 20 °C;

- a non-stick coating is sprinkled on the surface of the mold.

The overall appearance of the modeling results and the random shrinkage scale are shown in Figure 3.

a)

b)

Figure 3. The appearance of volumetric shrinkage gaps, which can be characteristic of the LVM Flow program of ball mill armor

a) ball mill external armor plotter b) ball mill medium armor plotter.

As can be seen from Figure 3 (a and b), volumetric shrinkage gaps arise from casting ball mill armor castings (shown in red). this significantly reduces the life of the armor during its operation.

The main reasons for the formation of these volumetric shrinkage gaps may be the following.

1. The feeding and output channels of the well are incorrectly designed.

2. Because mold material for casting was not chosen correctly, it was difficult for gases to escape from the mold.

3. The metal being melted is not heated to a sufficient temperature, etc.

In addition to the LVMFlow program, there are also very kolab programs, such as ProCast, Lumion, 3d Max. But the LVMFlow program is distinguished precisely by the fact that it is specially designed for the design of casting processes.

This study explored the hydrodynamic and thermophysical processes that occur in casting molds during the casting, crystallization and cooling of "Torres armor" (medium and external) castings using computer modeling.

In conclusion, we can say that the modeling of armor casting processes made it possible to process, analyze and select significantly faster and more economical options. Next, it is necessary to pour an experimental batch of armor on recycled technologies, as well as metallographic analysis of the macro and micro-structure of various parts of the zone of change in the density of cast metal. In addition, it is necessary to additionally study the mechanical properties of 110Г13Л steel in order to assess the residual stresses in the casting, which can also affect the smoothness of the armor.

References:

1. A. G. Doll / XXVIII International Mineral Process Congress// September 2016, Quebec City, Canada/ A. G. Doll https://www.sagmilling.com/articles/29/view/?s=1
2. Klas-Goran Eriksson Развитие систем мельничных футеровок / GunderMarklund, А.Л. Гребенешников, В.Ю. Фищев // Горная промышленность. – 2003. - № 1(43). http://www.http://miningmedia.ru/ru/article/drobilka/1623-razvitie-sistem-melnichnykh-futerovok
3. Liners for the Grinders/ Written by E & MJ News - URL: http://www.e-mj.com, // Published: Tuesday, 08 June 2010 15:04. (Дата обращения 22.05.2017).
4. D. Royston Semiautogenous grinding (SAG) mill liner design and development/ MINERALS & METALLURGICAL PROCESSING, Vol. 24, No. 3 • August 2007,р 121 – 132.
5. Modelling and simulation of dynamic behaviour in crushing plants: Technical report No. 75. Sweden: Chalmers University of Technology, 2013.