CN109290039B - Machining process for machine-made sand stone - Google Patents

Abstract

The invention discloses a machine-made sand processing technology, wherein stone is generally crushed firstly; a bar-shaped screen screening process is added in the screening step, and needle flaky particles in the semi-finished product are screened out, so that the needle flaky particles are accurately crushed and shaped; after the machine-made sandstone is screened, carrying out special grading adjustment based on standard grading requirements; the sand and stone material after grading optimization is pre-wetted and piled for more than 24 hours, and then washed by water to remove mud powder. The machine-made sandstone processing technology realizes the combined desilting and powdering of the needle-shaped flaky particles, the precise grading adjustment of the sandstone materials, the pre-wetting and water washing, systematically and economically solves the quality index problems of the machine-made sandstone grading, the particle shape, the mud content, the mud block content, the water absorption and the like, and provides a production technology with certain universality for the production of high-quality machine-made sandstone.

Description

Machining process for machine-made sand stone

Technical Field

The invention relates to the technical field of needle-shaped particle screening, grading adjustment, mud removal and powder removal of machine-made sand stones, in particular to a machining process of the machine-made sand stones.

Background

Sandstone is the resource with the largest exploitation amount in China. With the gradual exhaustion of natural sandstone resources, the mechanism sandstone becomes the main source of building aggregate. The common machine-made sand and stone processing mainly comprises coarse crushing, pre-screening, fine crushing and finished product screening, and a shaping process is generally required to be added for high-quality machine-made sand and stone. As shown in fig. 5.

The quality indexes such as sand-stone gradation, grain shape, mud block content, mud content and the like directly influence the working performance, mechanical property, durability and cost of the concrete. On the premise of qualified raw materials, in addition to control standards such as gradation, grain shape, mud content, mud block content, water absorption and the like, the machine-made sandstone production also needs to control indexes such as processing cost, yield and the like so as to improve competitiveness and save utilization resources. At present, indexes such as gradation, grain shape, mud block content, mud content and the like are difficult to be considered in the production of high-quality machine-made sandstone, and the outstanding problems of high cost, low yield, high energy consumption and the like are faced. The development of a high-efficiency production process of high-quality machine-made sandstone is a problem which is urgently needed to be solved in China.

Through the search of patent libraries, in recent years, the main patent application cases of the mechanism sand production technology are described as follows:

CN201610126701.9 "high-quality sandstone crushing production process method" proposes a high-quality sandstone crushing production process method: firstly, carrying out primary screening on sandstone aggregates, dividing the sandstone aggregates into different particle sizes, and respectively sending the sandstone aggregates into a reaction crusher for primary crushing and an impact crusher for secondary crushing; and then, performing secondary screening on the materials to produce a plurality of product materials, wherein the product materials exceeding the particle size requirement return to the upper stage for crushing and reworking, and performing tertiary crushing on a part of the product materials meeting the particle size requirement. According to the invention, incoming materials are subdivided, the working characteristics of various crushers are fully utilized, so that each crusher can simultaneously and efficiently stabilize full-load work, secondary or even tertiary treatment is carried out after product materials are subdivided, the yield of fine sand is improved, gravel is shaped, and the dust content of the gravel is controlled through a dust removal system, so that the extremely high quality of discharged gravel materials is ensured, and the requirements of various high-quality gravels in various industries can be met.

CN200410081460.8 semi-dry sand making process of artificial sand and stone system proposes a method of "wet first then semi-dry" and "grinding instead of breaking", that is, while grading the semi-finished product, washing the aggregate of various grades with high pressure water, removing the mud powder wrapped on the surface of the aggregate, grading and dehydrating the aggregate, selecting the aggregate with proper grain size as the sand making source, adopting vertical shaft type sand making machine to make sand, adding sand water and powder sand to recycle, controlling the moisture content of the aggregate in each link of the sand making process, thus achieving the semi-dry sand making, avoiding the defects of the dry and wet sand making, having less investment, realizing low investment and high output, better controlling the stone powder content, fineness modulus and moisture content of the sand, simultaneously eliminating dust atmospheric pollution, assisting the recovery and utilization of powder sand and waste water, increasing the yield of the sand and reducing the water consumption, being suitable for the construction of high-rolling concrete dam of hydropower station, meanwhile, the method can also be applied to the fields of highways, bridges, airports, industrial and civil buildings and the like.

CN201710047310.2 sandstone aggregate line and production method thereof, comprising a stone bin feed inlet, a feeder, a crude stone crusher, a gravel elevator, a gravel screening machine, a first bin, a second bin, a third bin, a sand bin, a fine bin, a sand making machine, a sand elevator, a sand screening machine, a powder bin, a gravel crusher, a dust collector and a dust output port, has the advantages of low energy consumption, short flow, few equipment platforms, small occupied area, low investment, less production labor and the like.

CN201410275689.9 floor standing type sand production system and sand production method relates to a floor standing type sand production system and sand production method. This building station formula grit production system includes feed mechanism, system sand machine, feeding mechanism, hoist mechanism and floor formula structure, and feeding mechanism carries the discharged material of system sand machine for hoist mechanism, and hoist mechanism's upper portion exit linkage is to the feed inlet of air sieve, and air sieve upper portion realizes grit preliminary classification and powder separation under the wind-force effect, and the air sieve lower part is equipped with the shale shaker that is used for the grit to grade accurately. This building station formula grit production system's simple structure, rationally distributed are favorable to reduce cost, improve production efficiency to can adapt to different production demands.

CN201410568383.2 machine-made grit production system and production method relates to a machine-made grit production system and production method, including feeder hopper, the batcher of feeder, be used for carrying out the rough broken system of primary breaking to the aggregate, be used for carrying out the broken system in once more to the aggregate, set up the system sand machine that is used for further broken aggregate behind the broken system in the middle, set up first screening behind the system sand machine, be used for satisfying the aggregate output of first granularity interval, unsatisfied aggregate of first granularity interval and return to the system sand machine after the grading adjustment system integer, connect through aggregate conveying system between each module. The method can improve the yield of the machine-made sand meeting the needed fineness modulus by controlling reasonable gradation, further reduce the content of needle flaky particles by a sand making machine and improve the quality of the machine-made sand.

CN 201510171685.0A concrete aggregate shaping technique, which is used for producing qualified concrete aggregates with granular forms. The method is characterized in that the original materials are changed into large materials with the diameter not exceeding the upper limit after primary crushing treatment, and the large materials are thrown and fall off in the roller continuously and collide with small materials entering the roller continuously for a long time for grinding in the washing rotary stirring process of the roller stone washer and the roller screen, so that the shaping and grinding effect of 'stone beating' on concrete aggregate is realized.

Retrieval results show that at present, the patents of the high-quality machine-made sandstone processing method are few, related patents mainly focus on the function exertion of specific equipment, and the description of the technological solution of the system is very few. Wherein: the particle shape optimization is not accurately performed on the needle-shaped particles; grading optimization is mainly carried out through a crusher, and a general process method is optimized for grading coarse aggregates with different lithologies; the treatment process of the mud removing blocks, mud powder and stone powder mainly utilizes high-pressure water washing or high-pressure air flow separation, and the effects of fast mud and mud powder high-pressure water washing or high-pressure air flow separation solidified on the surface of stone materials in actual production are not ideal.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the technical problems in the prior art, the invention provides a machining process for machine-made sand and stone, which can effectively reduce the content of needle-shaped particles of the machine-made sand and stone, optimize the product gradation, efficiently remove impurities such as mud blocks, mud powder, stone powder and the like in a sand and stone product, effectively ensure the saturated water absorption of a finished product and provide a process solution with general guiding significance for solving the difficult problem of high-quality machine-made sand and stone production.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a machining process for machine-made sand stones specifically comprises the following steps:

1) crushing raw materials to form mixed stones, grading and screening the mixed stones to divide the mixed stones into a plurality of semi-finished products with different standard specifications, and screening needle-shaped stones from each semi-finished product with different specifications to form finished stones with different specifications;

2) grading adjustment is carried out on finished stones with different specifications in the step 1), the step 4) is carried out on the mixture which meets the grading proportion of the finished stones, and the step 3) is carried out on the stones with overproof grading;

3) shaping and crushing the needle-shaped stone material in the step 1) and the stone material with the intermediate grade exceeding the standard in the step 2), and performing the step 1 again on the shaped and crushed stone material;

4) the stones which accord with the grading proportion of the finished products in the step 2) are firstly added with water until the humidity is 8-12%, and the stones are piled for not less than 24 hours, and then are washed with water to remove mud powder, mud blocks and redundant stone powder.

In the above method, preferably, in the step 1), the mixed stone is classified and sieved by vibrating the mixed stone through a multi-layer vibrating screen in the step 1).

In the above method, preferably, each layer of the multi-layer vibrating screen adopts a screen with different meshes.

In the above method, preferably, the mesh diameter of the screen is 0mm to 53 mm.

In the above method, preferably, in the step 1), the semi-finished product of each specification is screened out needle-shaped stone through a strip-shaped screen.

In the method, preferably, the length of the mesh of the strip-shaped screen is not less than 5 times of the width, the width of the mesh of the screen is not more than 0.6 time of the diameter of the mesh of the multilayer vibrating screen, the strip-shaped screen is provided with a plurality of arrangement ribs at intervals of 3-5 rows in the longitudinal direction, and the height of the section of each rib is not less than 4 times of the width.

In the method, preferably, the stone in the step 2) is graded through a material box, a vibrating feeder and a belt conveyor, the belt conveyor is provided with a belt scale, the mixture with single specification sequentially passes through the material box, the vibrating feeder and the belt conveyor, the feeding speed is changed by adjusting the vibration frequency of the vibrating feeder, and the mixture which meets the grading proportion of the finished product is the finished product.

In the method, preferably, the stone in the step 2) is graded and adjusted through a material distribution system with a material baffle and a belt conveyor, the belt conveyor is provided with a belt scale, the mixture with a single specification sequentially passes through the material baffle distribution system and the belt conveyor, the material distribution ratio is adjusted by changing the material baffle feeding area of the material distribution system, and the mixture according with the finished product grading ratio enters a finished product pile.

The invention provides a machine-made sand stone processing technology, which is characterized in that raw materials meeting the requirements of standard documents such as GB/T14684 construction sand, GB/T14685 construction pebble and gravel and the like are crushed to form a machine-made sand stone semi-finished product, a bar-shaped screen screening process is added to the semi-finished product screening technology, needle-shaped particles are screened out, and the needle-shaped particles are precisely shaped and crushed; based on the grading standard, a special method is used for carrying out grading adjustment on the machine-made sandstone semi-finished product; the sand and stone material is pre-moistened and then washed by water, and the mud block, mud powder and stone powder are efficiently removed.

Drawings

FIG. 1(a) is a schematic view of a structure of a bar-shaped screen.

Fig. 1(b) is a schematic top view of the structure of fig. 1.

Fig. 2 is a schematic structural diagram of integration of the classification screening and the needle sheet screening.

Fig. 3 is a schematic structural diagram of a bin, a vibratory feeder and a belt conveyor.

Fig. 4 is a schematic structural diagram of a striker plate material distribution system.

FIG. 5 shows a prior art process for machining sand

FIG. 6 is a schematic diagram of a production process of fine materials in a mine from Jiangsu Zhenjiang.

FIG. 7 is a graph comparing sand from a prior art process with sand from a process of the invention.

Fig. 8 is a prior art sand making system process flow.

Fig. 9 is a process flow of a sand making system of the present invention.

The reference numbers in the figures illustrate:

1. a strip-shaped screen; 2. longitudinal plate ribs; 3. a needle sheet particle channel; 4. a strip-shaped screen for screening needle-shaped particles; 5. a screen mesh for ordinary classification; 6. vibrating screen; 7. a material box; 8. a vibrating feeder; 9. qualified belt conveyor; 10. a belt scale; 11. a striker plate; 12. a multilayer needle sheet-shaped particle vibrating screen; 13. a strip-shaped screen; 14. qualified material belt conveyor.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The machine-made sandstone processing technology specifically comprises the following steps:

1) selecting raw materials meeting the requirements of standard documents such as GB/T14684 construction sand and GB/T14685 construction pebble and gravel;

2) the raw materials are subjected to coarse crushing, fine crushing, shaping and screening to form machine-made sandstone materials with different standard specifications;

3) screening each single-specification sand and stone material formed in the step 2) through a multilayer vibrating screen, dividing each single-specification sand and stone material in the step 2) into 2-4 fine-specification stones, spreading the thickness of a material layer on a strip-shaped screen during subsequent needle-sheet screening, and defining mesh parameters of the screen mesh of the multilayer vibrating screen in a particle size range of the single specification to be screened;

referring to table 1 for mesh parameters of the screen, and defining nonstandard mesh parameters within a mesh parameter range of 0-53 mm according to requirements;

TABLE 1 Standard Screen mesh parameters

Numbering	Grading interval (mm)	Standard mesh parameters of screen (mm)
			1	0-2.36	2.36
2	2.36-4.75	4.75
			3	4.75-9.50	9.5
4	9.5-13.2	13.2
			5	13.2-16.0	16
6	16.0-19.0	19
			7	19.0-26.5	26.5
8	26.5-31.5	31.5
			9	31.5-37.5	37.5
10	37.5-53	53

4) Screening needle-shaped stones from each semi-finished product with the subdivided specification in the step 3) through a strip-shaped screen 1 to form finished stones with different specifications; the length of the mesh of the strip-shaped screen 1 is generally not less than 5 times of the width, and the width is not more than 0.6 times of the diameter of the mesh of the multilayer vibrating screen; the strip-shaped screen mesh 1 is provided with a longitudinal plate rib 2 at intervals of 3-5 rows in the longitudinal direction, and the height of the section of the rib is not less than 4 times of the width, as shown in fig. 1(a) and (b);

the needle-shaped screening can be carried out independently, and can also be combined with a front-end multilayer vibrating screen (as shown in figure 2); when combined for use, the device comprises a strip-shaped screen 3 for screening needle sheet-shaped particles, a common screen 4 for classification (the screen is a square hole or a round hole), and a vibrating screen 5, wherein the needle sheet-shaped particles screened and separated by the strip-shaped screen return to a shaping and crushing system through a needle sheet-shaped particle channel 6;

5) according to quality standards or requirements of customers, different stones after needle-shaped stones are screened out can be graded and adjusted by the following two schemes:

firstly, stone is graded and adjusted through a material box 7, a vibrating feeder 8 and a belt conveyor 9, the belt conveyor 9 is provided with a belt scale 10, the mixture with single specification sequentially passes through the material box 7, the vibrating feeder 8 and the belt conveyor 9, the feeding speed is changed by adjusting the vibration frequency of the vibrating feeder 8, and the mixture which accords with the grading proportion is a finished product;

secondly, the stone is graded and adjusted through a material distribution system with a material baffle plate 11 and a qualified material belt 14, the material distribution system is positioned behind a needle-shaped particle vibrating screen 12, the belt conveyor 14 is provided with a belt scale 10, the single-specification stone passes through the material baffle plate material distribution system, the material distribution ratio is adjusted by changing the feeding area of the material baffle plate 11 of the material distribution system, and the qualified material which meets the finished product grading ratio enters a finished product pile through the belt conveyor 14;

6) grading adjustment is carried out on stones of each specification, the step 8) is carried out on the mixture which meets the grading proportion of the finished product, and the step 7) is carried out on the mixture which exceeds the grading;

7) shaping and crushing the needle-shaped stone materials in the step 4) and the mixture with the intermediate grade exceeding the standard in the step 6), and performing the step 1 again on the shaped and crushed stone materials;

8) and 6) adding water into the mixture according with the finished product grading proportion until the humidity is 8% -12%, stacking for no less than 24 hours, washing with water, removing mud powder, mud blocks and redundant stone powder, and performing saturated water absorption on the finished product stone.

Example 1

Mine application case of stone material of Jiangsu Zhenjiang

The mine is mainly used for producing high-quality machine-made sand stones, and is mainly used for highway pavement materials, special concrete materials and the like. The flow of the mineral process according to the present process is shown in fig. 6. Wherein, the screening process firstly utilizes 3 × 3mm, 5 × 5mm, 10 × 10mm, 16 × 16mm and 25 × 25mm square-hole screens to screen into 0-3mm, 3-5mm, 5-10mm, 10-16 mm, 16-25mm and other specifications, and the 3-5mm, 5-10mm, 10-16 mm and 16-25mm square-hole screens are respectively screened through 2 × 16mm, 3 × 25mm, 5 × 40mm and 8 × 60mm strip-shaped screens. Needle-shaped stone materials screened by the strip-shaped screen enter a vertical shaft impact crusher for shaping and crushing, and return to a screening system to realize closed cycle. The product has a needle shape of less than 1%; the installed power of the screening and shaping process is reduced by about 35 percent compared with that of the common screening and shaping process.

Example 2

Zhejiang lake certain mine application case

The enterprise utilizes common stone materials to process fine stone materials. During ordinary stone processing, water is firstly added according to the proportion of 8-12% for wetting, and the stone is conveyed to a raw material pile in a fine work workshop for storage for about 24 hours, and when fine products are produced, raw materials enter a shaping processing line for shaping, screening and screen water flushing. The content of the produced fine mechanism sand-stone mud powder is less than 1 per mill (less than 5 per mill of standard), the comprehensive water consumption per ton finished product is 0.52 cubic, and the product is widely applied to high-speed rails, pipe piles, high-rise buildings and the like.

Example 3

Application case of a mine in Lanzhou Gansu province

(1)5-10mm stone grading optimization

The 5-10mm screening in the early stage of the enterprise adopts a two-layer screen, the screen mesh parameters are 10 x 10mm and 5 x 5mm, and the 5-10mm grading is not up to the standard all the time due to the low screening rate of 5 mm. Based on the process, a layer of 6.5mm screen is added between the two layers of screens through transformation, and the screening efficiency of 5mm is improved by 25%. Meanwhile, at the discharge end of the vibrating screen, a hydraulic push rod is added to push the material baffle plate to distribute materials, part of 5-6.5 mm stones are removed, and 5-10mm stone gradation is better optimized, as shown in fig. 7.

(2) Sand making system optimization

The enterprise sand making system is improved, wherein the raw materials mainly comprise 5-10mm stones, not less than 20% of 0-5 mm original coarse sand is doped, the product is medium sand, the fineness modulus is 2.8 +/-1.5, the sand forming rate is 75%, and a process flow chart is shown in fig. 8. According to the process, 0-5 mm undisturbed coarse sand is sieved into 0-3mm medium sand and 3-5mm stone chips by a 3mm sieve, the 3-5mm stone chips and 5-10mm stone materials are mixed together to form 0-5 mm medium sand, and then the 0-3mm medium sand formed by 3mm sieving is doped, and the process flow is shown in figure 9. Through improvement, the usage amount of coarse sand with the thickness of 0-5 mm is close to 60%, the yield of a sand making system is increased by 60%, and the product is medium sand, the fineness modulus is 2.8 +/-1.5, the void ratio is less than 42%, and the sand forming rate is 86%.

The foregoing is considered as illustrative of the preferred embodiments of the invention and is not to be construed as limiting the invention in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.

Claims (3)

1. A machining process for machine-made sand stones is characterized by comprising the following steps: 1) crushing raw materials to form mixed stones, grading and screening the mixed stones to divide the mixed stones into a plurality of semi-finished products with different standard specifications, and screening needle-shaped stones from each semi-finished product with different specifications to form finished stones with different specifications; 2) grading adjustment is carried out on finished stones with different specifications in the step 1), the step 4) is carried out on the mixture which meets the grading proportion of the finished stones, and the step 3) is carried out on the stones with overproof grading; 3) shaping and crushing the needle-shaped stone material in the step 1) and the stone material with the intermediate grade exceeding the standard in the step 2), and performing the step 1 again on the shaped and crushed stone material; 4) adding water into the stones according with the grading proportion of the finished products in the step 2) until the humidity is 8% -12%, stacking for no less than 24 hours, and then washing with water to remove mud powder, mud blocks and redundant stone powder;

classifying and screening the mixed stone through vibration of a plurality of layers of vibrating screens;

each layer of the multilayer vibrating screen adopts a screen with different meshes;

the diameter of the mesh of the screen is 0-53 mm;

screening needle-shaped stone materials from the semi-finished products of each specification through a strip-shaped screen in the step 1);

the length of bar screen cloth mesh is not less than 5 times of width, the width of screen cloth mesh is not more than 0.6 times of multilayer shale shaker mesh diameter, bar screen cloth vertically sets up an arrangement rib every 3 ~ 5 rows at an interval, and rib cross-section height is not less than 4 times of width.

2. The machine-made sandstone processing technology of claim 1, wherein the stone in the step 2) is graded through a material box, a vibrating feeder and a belt conveyor, the belt conveyor is provided with a belt scale, the mixture with single specification sequentially passes through the material box, the vibrating feeder and the belt conveyor, the feeding speed is changed by adjusting the vibration frequency of the vibrating feeder, and the mixture which meets the grading proportion of the finished product is the finished product.

3. The machine-made sandstone processing technology of claim 1, wherein the stone in the step 2) is graded and adjusted by a material distribution system with a material baffle and a belt conveyor, the belt conveyor is provided with a belt scale, the mixture with single specification sequentially passes through the material baffle distribution system and the belt conveyor, the material distribution ratio is adjusted by changing the material baffle feeding area of the material distribution system, and the mixture according with the grading ratio enters a finished product pile.

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