Crushed Stone Production Shop Plan - Exchange Rate

Contents

Introduction

Crushed stone is the most widely used product of extraction and processing of non-metallic building materials.

Global crushed stone production exceeds 3 billion m3 per year. An interesting feature of crushed stone as a product produced from natural mineral raw materials is that its prices around the world over the past 50 years have increased 2.5-3 times. At the same time, prices for most mineral-based products (for example, ferrous and non-ferrous metals) fell 3-5 times during the same time.

The seemingly simple production of crushed stone - crushing rocks - is deceptive, since modern technologies for the production of building materials and products based on them place increasing demands on the quality of crushed stone, used mainly as aggregate in the production of concrete, asphalt concrete and road surfaces.

The factory produces crushed stone of fractions 020, 20-60, 520. Crushed stone production is associated and necessary in the main production chain of the enterprise. The main production is the extraction and processing of iron ore. The necessary DSF is because it participates in the processing of iron quartzite-rich ore from which it produces agglore, the waste of which is crushed stone and also processes low-rich ore from which crushed stone is also obtained.

Mining enterprises develop mineral deposits for various purposes. Despite the existing differences in mining and geological conditions and technologies for development and processing, mining industries must solve the same problems, listen to the emotional speeches of people who consider the exploitation of the subsoil to be a universal evil and seek to ban almost all types of mining. Although it should be recognized that miners are not always careful and are economically related to natural resources, environmental protection. But ecology is not the only and not the most acute problem of the domestic mining industry. The differences between the various sectors and sub-sectors of the mining industry can be quite significant, which determines the differences not only in mining and mineral processing technology. In the non-metallic building materials industry, the following provisions are particularly relevant:

differences in physical and mechanical properties of minerals, for example, high strength of eruptive rocks (250300 MPa or more) and sands. This determines the variety of technologies and equipment used;

a large number of enterprises, their number is measured by many thousands;

rigid connection between the work of the quarry and the crushing and sorting plant;

the desire to preserve the strength of the mined rock, to prevent its re-grinding (since fine fractions often constitute enrichment waste), and in some cases to preserve its decorative properties.

Crushed stone for concrete production

Crushed stone as a large aggregate of concrete, forming a rigid skeleton, increases its strength and deformation modulus, reduces creep, shrinkage, increases its durability, and reduces cement consumption.

Fine aggregate - sand - affects the rheological properties of the concrete mixture - viscosity, ultimate shear stress of concrete, as well as its density.

The shape of coarse aggregate grains directly affects the workability of the concrete mixture. In addition, crushed stone with grains of flat (hazel) or needle shape has a significantly greater emptiness than crushed stone with cuboid-shaped grains. According to VNIIZhizelezobeton, the bulk weight of crushed stone with a content of flat and needle-shaped grains is up to 15% lower than crushed stone with cubic-shaped grains.

The bulk weight of crushed stone, consisting entirely of flat or needle-shaped grains, is 9-10% lower than crushed stone with cuboid grains. These factors cause an increase in cement consumption. Therefore, although the shape of coarse aggregate grains, according to a number of studies, does not significantly affect the strength of concrete, serious attention should be paid to it.

In crushed stone for road concrete, the content of grains of flat and needle shape is allowed up to 25%, for asphalt concrete - up to 15%, for the bases of roads (unprocessed) - up to 25%.

It should be noted that the accepted limitation of the content of flat and needle-shaped grains in the crushed stone with a ratio of larger and smaller sizes above 3 does not fully characterize the grain shape. In this regard, it is of interest that some foreign standards estimate the shape of grains according to the so-called "shape index," that is, the average ratio of the largest and smallest grain sizes of a sample. This assessment allows you to judge the shape of the entire quantity

Characteristics of the enterprise

The amount of DSF products produced is stable and in constant demand, so there is no stock of crushed stone at the warehoused sites. The total volume is 22.8 thousand m3 per year, fractions 020.

Dense rocks are fed from the quarry to the transshipment warehouse.

DSF by rail according to the weekly production schedule.

Dense rocks with a size of 01200 mm from the transshipment depot to the DSF receiving bin are supplied by dump trucks. The capacity of the receiving hopper is 200 tons, which corresponds to the hourly reserve. Raw material is supplied from receiving hopper by plate feeder 124120 to jaw crusher SchKD 1500 * 2100 with preliminary screening on grate screen with fan-shaped grates and slot between them up to 120 mm. The feeder capacity is adjusted continuously by changing the motor speed by means of a frequency converter. Width of unloading slot of crusher SchKD 180200 mm. The size of the crushed product is 0350 mm.

Sub-sieve and crushed products are combined into HP No. 2 and belt conveyor No. 15 are supplied to an intermediate middle crushing hopper with a capacity of 80 tons. From the shale hopper, a plate feeder 21245 with a stepless control of the belt speed is supplied to the GIT53S No. 4 screen. The following types of screening surfaces are installed on the screen: the upper deck is rubber-wound sieves made at the RMZ of Stoilensky GOK OJSC from a conveyor belt, with a slot width of 60 mm; middle deck - elastic sieving surfaces with a square cell with a size of 70 * 70 mm; lower deck - elastic screening surfaces with a square cell with a size of 25 * 25 mm (20 * 20 mm and 30 * 30 mm) depending on the required size of the finished product. The upper tier of the sieve serves to protect the EPG from gusts and wear when a 0350 mm piece falls. The oversized product of the upper and middle tier of sieves enters the KSD2200 Gy crusher, which has a range of control of the unloading slot of 3060 mm. Crushed product with a system of conveyors luk 12a, luk No. 12, luk No. 13 and luk No. 14 is supplied to silo No. 3 of fine crushing with a capacity of 80t. The oversized product of the lower tier of the GIT53S screen with a size of 2060 mm is transported to the floor warehouse of the finished product by conveyors lock No. 10, luk No. 27 and luk No. 28a. Material is unloaded from conveyor by means of movable autostell on both sides of conveyor. The material is stored in cones before the pylon is filled. In case of full filling of spans No. 1 and No. 2 with crushed stone of fraction 2060 mm, it is possible to direct the material to conveyors No. 28 and No. 29 by rearranging the gate in the loading leak of lux No. 27, and storage in spans No. 3, No. 4, No. 5, No. 6.

The undersize product of the lower tier of the screen with a size of 020 mm is delivered to the conveyor frame No. 16 and then through the conveyors frame No. 16a and frame No. 28b is supplied to the warehouse in spans No. 7 and No. 8. The loading of spans No. 7 and No. 8 is carried out similarly to the 2060 mm fraction. To separate the mixture of 020 mm fractions into separate fractions, it is possible to install the GIT51 screen at the place of material overload from lux No. 16a on lux No. 28b.

The oversized product of the upper and lower tiers of the GIST 53C screen with a size of 0100 mm from bin No. 3 of fine crushing by feeders 21245 with stepless control of the belt speed is supplied to the two-screen screen screen GIT52M No. 3. Screen is equipped with the following types of screening surfaces: upper deck - EPP with cell 70 * 70 mm, lower deck - EPP with cell 25 * 25 mm (20 * 20 mm, 30 * 30 mm). The oversized product of the upper tier of sieve with a size of 60100 mm falls into the small crusher KMD2200 T1 with a control range of the unloading slot of 515 mm and then on the conveyor luk No. 12a, where it is combined with the crushed material of crusher No. 4, and with conveyors luk No. 12, luk No. 13 and luk No. 14, bunker No. ker No. 3 returns, forming a closed cycle.

The oversized product of the lower tier of sieves enters the conveyor tray No. 10, where it is combined with the finished product with a size of 2060 mm after screening in the medium crushing stage.

The sub-sieve product with a size of 020 mm enters the conveyor lock No. 16, where it is combined with the sub-sieve product of screen No. 4.

To remove the rash from the feeders No. 3 and No. 4, a conveyor rack No. 18 a is installed, the unloading of which takes place on the ramp No. 12.

Crushed stone of the mixture of fractions 2060 mm must meet the requirements of specification 57110150018682602. The product of the 020 mm mixture shall meet the requirements of specification 5711018001868262004. The amount of processed product is taken into account by the weights: for the mixture of fractions 2060 mm - EKV-4D, installed on conveyor lock No. 26, for the mixture of fractions 020 mm - VKE-2, installed on conveyor lock No. 16a.

The readings of the scale are entered hourly by the operator of the control panel in the operational log of crushed stone processing.

The accuracy of operational accounting of production is monitored in accordance with the operational accounting provision.

The circuit diagram of DSF sets is given in Appendix B.

Main process requirements:

Crushing and screening

When crushing rock in cone crushers, the following requirements shall be met:

- initial power supply size shall not exceed 0.85 of receiving slot width;

- crushers shall ensure production of crushed product with the following limit coefficient of reinforcement:

1) for conical crushers of medium crushing - 2.9;

2) for fine crushers - 3.8.

If these factors are exceeded, it is necessary to adjust the unloading slot or replace the armor of the crushing cones.

During screening operations:

- presence of torn sieves;

- increase of holes of sowing surfaces as wear increases by more than 30%.

Screen performance and efficiency must be consistent with the map.

The diagram of the whole process is given in Appendix B.

Equipment characteristics in Appendix B.

Conclusions

Enterprises of developed countries widely use mobile and self-propelled complexes that carry out partial or complete (in the case of production of non-solid building materials) processing of rock mass. Such complexes began to be used in our country. For foreign enterprises, the device of modular type crushing and sorting complexes in open design is typical. But the vast majority of domestic enterprises use outdated technologies - crushing and sorting plants and enrichment plants are bulky phonodomous heated structures.

1. The strength of concrete when using cuboid crushed stone increases by 5-10% with a simultaneous decrease in cement consumption by 7-12% and a decrease by 3-5% in the water demand of the concrete mixture.

2. Standard cheek and cone crushers do not provide the necessary crushed stone shape.

3. Impact-centrifugal crushers-granulators reduce the content of hazelnuts in crushed stone to the requirements of standards, but can be used as an additional crushing step - "cubicator."

4. Conical inertial crushers provide cuboid crushed stone in a wide size range with a minimum number of crushing stages

The mining industry of construction materials should take into account the opinion of consumers. In respect of non-metallic construction materials, their claims relate to the quality of the products and their nomenclature. Claims to the quality of non-solid building materials mainly relate to the consolidation of crushed stone and gravel fractions, exceeding the standard content of pulverized and clay particles, clumps of clay, weak grains. And also to insufficient volumes of crushed stone output of the 1st and 2nd groups. If the number of main consumers is reduced to three categories (concrete, roads and railways), then the ratio of the share of non-metallic construction materials consumed by these main groups will be 45.45 and 10%, respectively. That is, a significant part of the rubble of the 1st and 2nd groups is required for the construction and repair of roads and railways. The likely areas of development of the mining industry of construction materials include: expansion of the product range; to the greatest extent, the expansion of the nomenclature relates to the production of non-metallic construction materials, complex use of mineral resources of deposits, introduction of flexible process lines on mines of non-ore building materials, mainly using mobile and self-propelled crushing and sorting units, creation of new layout solutions of processing complexes with remote control, expansion of use of rock crushing screenings, creation of domestic equipment allowing small-capacity enterprises to produce competitive products, re-creation of a product quality management system on new principles, application of technological schemes for extraction and processing of mineral raw materials, corresponding to the principle: one process - one machine.

The management of enterprises needs operational information about the change in demand for mineral products. That is, answers to questions about which types of products there is unmet demand, whether it is necessary to expand the range or change some characteristics of the produced products. Enterprises cannot develop without the prospect of technical re-equipment. To do this, you need to have an idea of ​ ​ the nomenclature and characteristics of products that will be in demand in the future for 1015 years or more - in a period that can be covered by long-term forecasting based on consumer requests.

crushed stone grains.

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