Material specification:
1. carbon & low alloy steel;
2. stainless steel;
3. high alloy & wear resist steel;
4. gray iron; ductile iron;
5. malleable iron;
6. alloyed cast iron;
7. aluminum alloy;
8. cooper alloy;
9. zinc alloy
Range of casting weight: 0.50kg-450kg
Heat Treatment: Normalizing
Quenching
Tempering
OUR MACHINING PROCESS :
lOccupies an area more than 6,000 square meters
lMore than 40pcs big CNC lathes Ø500 - Ø1200
lMachining center 1400 x 825 x 1000mm 4 axis
Can provide services: turning; milling; grinding; drilling; inserting; broaching; boring; polishing
Surface preparation: passivation; polishing; plating; coating; painting; zinc phosphate; dacrotized / dacromet technology
Our inspection equipments: Spectrometer Analyzer; Magnetic Particle Inspection; Brinell Hardness; Ultrasonic Inspection; Liquid Penetrate Inspection, Low Temperature Impact Tester; Universal Tester, Hydraulic Pressure Tester, CMM and etc.
Precision Casting,Lost Wax Casting,Stainless Steel Turning Parts,Customized Turning Parts Baoding Henglian Mechanical Co.,Ltd , https://www.hengliancasting.com
Study on the site and distribution plan of the accumulation type bauxite mine
Our country is both rich in bauxite resources in the country, it is also one of the country need more aluminum content. Currently, aluminum has become the second of the main metal after the steel, gold color occupies more than 40% of total saturation. The accumulation type bauxite is the main source of metal aluminum production in South China. The ore must be washed to the washing plant for ore dressing and ore before smelting to ensure the ore has a suitable and stable ratio of aluminum to silicon (Al). 2 O 3 grade and the ratio of SiO 2 grade). With the continuous development of mining, some stacked bauxite mines are facing resource replacement. How to comprehensively plan the proven new resources and the old resources that will be mined, and achieve a reasonable match between the stope and the washing plant, so as to achieve The possibility of using low-grade ores to extend the service life of mines has become an urgent problem for these mining enterprises. This study uses modern logistics planning, operations research and system engineering ideas to unify the washing plant site and ore blending program from a macro perspective, and establishes an optimized model of mixed integers, which has been successfully implemented in an actual stacked bauxite mine. application.
First, the abstraction of the problem
There is n mining unit for a certain type of bauxite mine, the original ore quantity of the i-th mining unit is C i , the service life of the mine is N; m alternative washing plant positions, the jth position is recorded as X j . The cost of building a washing plant here is F j . The annual processing capacity of the original ore after the completion of the washing plant is q j . The annual ore amount transported by the i-th mining unit is C ij , and the corresponding post-wash net ore. The amount is C' ij (net yield rate h i ), the grades of Al 2 O 3 and SiO 2 are A j and S j , and the net ore from all mining units passes through the ore yard of the washing plant. The annual output of the finished ore that is sent to the smelting after crushing and blending is P j , and the ratio of aluminum to silicon is between K 1 and K 2 ; the total amount of raw ore processed in each washing plant is Q 1 per year, after washing The total net ore is Q 2 ; the distance between the i-th mining unit and X j is D ij , the distance between X j and the smelter is D j ; the unit transportation cost of the truck is a. The production process of bauxite products is shown in Figure 1.
Figure 1 Production process of stacked bauxite products
The question now is: which washing plants should be built and how to properly arrange the annual production plans of each stop and washing plant, in order to ensure that the aluminum-silicon ratio of bauxite products sent to the smelting plant meets the design requirements. Minimize investment and transportation costs for construction.
Second, the comprehensive optimization mathematical model of the washing site and the ore distribution plan
As mentioned above, the core of the research is to determine the number and location of suitable washing plants under the premise of ensuring that the aluminum-silicon ratio of the ore-matching products meets the design standards, so as to achieve the minimum investment and construction and transportation costs of the washing plant. purpose.
The value of the original ore mined from the stope is very low. If the washing plant is too far from the stope, the freight of the ore in the washing plant will be too high, which will cause the product of the washing plant to lose its value-added space. Therefore, it is necessary to the i-th production unit alternatively be limiting and washing plant location between the distance D ij X j, X j and D ij is set depending on a switching variable, when the overrun is not D ij X j and the selected value of 1, when the When D ij exceeds the limit, X j is selected and assigned a value of 0 to solve the problem of the number and location of the washing plant. In addition, the upper and lower limits of the ore of the ore after the ore can be adjusted to reasonably match the rich ore. Lean ore is used to the maximum extent, while ensuring that the ore output from each ore distribution yard meets the smelter's aluminum-to-silicon ratio requirements.
According to the assumptions in Section 1 and the above ideas, it can be concluded that the total cost of building a washing plant and production transportation for a certain type of bauxite mine during the service period is
The corresponding constraints are:
(1) The total amount of raw ore mined by the i-th mining unit during the mine service period
(2) Truck transportation distance from the i-th mining unit to the jth alternative washing plant
Dij ≤ L,
(3) Assignment of the position of the jth alternative washing plant
Xj=1 (selected) or 0 (dismissed) (j=1, 2,...,m),
(4) The annual processing of raw ore in the jth washing plant
(5) The net mining rate of the ore mine from the i-th mining unit by the jth washing plant
Hi=(C' ij /C ij )×100%,
(6) Annual output of finished ore from the ore yard of the jth washing plant to the smelting plant
(7) The ratio of aluminum to silicon in the ore yard of the jth washing plant
(8) Annual total amount of ore processed by m washing plants
(9) The total amount of ore processed in m distribution sites
In this way, according to the principle of minimum investment in construction and production and transportation of washing plants, a comprehensive optimization mathematical model for the site and distribution plan of the stacked bauxite washing plant can be established.
Third, application examples
There are 42 mining units and 3 alternative washing plants in an actual stacked bauxite mine. The deposits of each mining unit and the distance from each alternative washing plant are shown in Table 1. The design processing capacity and construction cost of each alternative washing plant are shown in Table 2.
Table 1 Deposits of each mining unit and the distance from the alternative washing plant
Mining list
No serial number
Preserving the original ore amount / 10,000 t
Total net ore after washing / 10,000 t
Washed ore grade /%
To the alternative washing plant transport distance / (10 -3 km)
Al 2 O 3
SiO 2
To X 1
To X 2
To X 3
1
2
┆
42
4.6740
67.1659
┆
8.7459
1.86960
26.86636
┆
3.49836
86.26
84.28
┆
81.08
9.20
11.28
┆
14.65
4350.180
3492.979
┆
9570.024
7865.217
7008.016
┆
6532.396
1504.898
8598.146
┆
5084.180
total
2750.2950
1100.11800
Table 2 Annual processing capacity and construction cost of the alternative washing plant design
Alternative washing plant location
X 1
X 2
X 3
Annual processing capacity q j / million t
Construction cost F j / million
90
20000
105
21300
95
20950
The service life of mine design 11a, the total processing job washing plant raw ore Q 1 is 2.5 million t / a, the total output of the task Q 2 is washed ore 1,000,000 t / a, with integrated minerals The aluminum-to-silicon ratio is 10±0.5, the unit transportation cost of the truck is 12,000 yuan/(10,000 t·km), and the single transport distance from the mining unit to the washing plant is 11 km, located at X 1 and X 2 . The distance from the three alternative washing plants at X 3 to the smelter is 34.7km, 34.8km and 3km respectively. It is required to determine the number and location of the washing plants and to arrange the years of each mining unit and washing plant. The production plan minimizes the investment and production and transportation costs of the washing plant, and ensures that the aluminum-to-silicon ratio of the ore blending products of each washing plant meets the design requirements.
The known conditions were substituted into the integrated optimization mathematical model of the accumulation type bauxite washing plant site and ore distribution plan, and the Dash Optimization software was used to solve the solution. The results are shown in Table 3.
Table 3 Calculation results
variable name
value
variable name
value
variable name
value
variable name
value
minF
Q1
Q2
X1
X2
X3
C(1,1)
C(2,1)
C(3,1)
C(4,1)
C(5,1)
C(6,1)
875357
250
100
1
0
0
0.4249
6.106
8.6785
6.7920
12.5719
4.415.3
C(7,1)
C(8,1)
C(9,1)
C(10,1)
C(11,1)
C(12,1)
C(13,1)
C(14,1)
C(15,1)
C(16,1)
C(17,1)
C(18,1)
13.9644
3.5108
6.5542
16.3778
7.0202
7.8822
24.3702
6.1299
10.6006
10.5779
3.1672
5.8375
C(19,1)
C(20,1)
C(21,1)
C(22,1)
C(23,1)
C(24,1)
C(25,1)
C(26,1)
C(27,1)
C(28,1)
C(29,1)
C(30,1)
3.7922
4.1683
21.7519
1.8961
2.0356
1.4621
2.9068
0.1910
0.0351
0.0937
0.9400
5.1418
C(31,1)
C(32,1)
C(33,1)
C(34,1)
C(35,1)
C(36,1)
C(37,1)
C(38,1)
C(39,1)
C(40,1)
C(41,1)
C(42,1)
0.6911
4.9106
8.6051
9.5356
3.8387
0.2523
2.3108
18.7689
0.1109
0.7848
0.7951
0.6911
Note: C(i,1) means Cil.
It can be seen from Table 3 that during the whole service period of the mine, only one washing plant located at X1 needs to be established. The total cost of construction and production transportation is 875.357 million yuan; the plan for the i-th mining unit to be transported to the washing plant The annual ore volume is C(i,1); the annual output of the post-washing ore mine used for the ore dressing is 1 million tons. This scheme has been successfully applied in the pre-production of an actual stacked bauxite.
Fourth, the conclusion
For some stacked bauxite mines facing resource replacement, it is the common goal to extend the service life of the mine and obtain the maximum economic benefits as far as possible to ensure that the aluminum and silicon of the ore blending products meet the design requirements. Based on the modern logistics planning, operations research and other theories, combined with the practice experience of mine production, this study established a comprehensive optimization mathematical model of the accumulation type bauxite mine washing plant site and ore distribution plan, which achieved the following objectives:
(1) Under the condition that the resource reserves and distribution are known, the location and number of the washing plant are determined, and a reasonable match between the stope and the washing plant is realized.
(2) By rationally blending ore of different grades, it not only realizes the mining of rich and poor mines, reduces the production cost, prolongs the service life of the mine, and ensures that the aluminum-silicon ratio of the ore-matching products meets the requirements.
(3) The constraints of this model are more common, and mining enterprises can flexibly adjust the annual operation plan according to actual production conditions, thus achieving the most cost-effective purpose.
(4) The scope of application of this model can be extended by increasing or decreasing the constraints.