The limestone mine homogenization mining technology

1 mine geological and production situation

1.1 mine geological survey

Vanda dragon cement limestone mining company is located in the northern suburb of xuzhou city, belongs to the Cambrian zhangxia group, the orebody strike things, to a length of 1428 m, tends to the south, 12 ~ 20 degrees Angle, orebody width of about 680 m, 242 m thick, on average, proven reserves industrial 86.31 million t stripping quantity 10.7 million t, the average stripping ratio is 0.124:1, debris mainly for magnesia limestone.

The mine is composed of five natural seam, bottom-up number 1 ~ 5, respectively, the quality of ore deposits is shown in table 1.

The table 1 shows that l, no. 2 and no. 3 seam CaO content is higher, low content of MgO style, the standard deviation of CaC03 is low, to illustrate the three deposits ore quality is better, less volatile, as I grade ore; No. 2 and no. 4 seam CaO content is low, high content of MgO style, the standard deviation of CaC03 is higher also, that the poor quality of the two ore deposits, the quality fluctuation is large, for magnesia Ⅱ grade ore.

1.2 profile of mine production

According to the mining design scheme, the lowest mining level 30 m, the highest elevation of 150 m. Minutes and eight period of mining, the period of 15 m height, is now 105 m and 90 m two period, three mining area, of which 105 m section two mining area. 90 m section of a mining area, is equipped with 3 sets of 4 m3, 18, 20 t mine dump truck scale of mining 1.6 million t, broken into the plant by the belt.

Due to the quality of mine is complicated, the quality of ore into the factory has been unstable, stripping quantity is bigger also, mine production, it is difficult for cement production has brought certain difficulty. Mine production situation in 2001-2003 are shown in table 2.

The table 2 shows that ore quality volatile into the factory in 2001-2003, stripping quantity many, has obviously improved the production cost. Ore into the factory in order to guarantee the quality of basic stability, minimize stripping quantity, make full use of the mining resources, reduce production cost, it is necessary to the mine with homogenization extraction method.

2 year homogenization ore matching planning method

2.1 mineralized digital model

In order to get a comprehensive understanding of the mass distribution of the mine, and plan for the annual homogenization ore matching formulation provides the basis of the data, we improved kriging method is adopted to establish the mathematical model of mineralization will mine in every stage of discrete into 15 * 15 * 15 m ore block, by calling the mine geology database of geological data, calculated from the microcomputer GeKuang piece of quality indicators: CaO and MgO style and CaC03 standard deviation, and the data deposited in the period of layered file. A layered file form, we use the drawing machine draw the quality distribution period, through quality distribution period, fully reflect the machines: optimization of CaO and MgO style and CaCO, the distribution of standard deviation.

2.2 the preparation of annual homogenization ore matching plan

Cement production requirements into the factory ore quality is stable, can't appear the quality fluctuation of big otherwise will affect the thermal system and the quality of cement kiln, therefore. Annual homogenization ore matching calculation model produced per year ore quality equilibrium as the goal, the mathematical model for:

The end condition

C1K1 + C2K2 + C3K3 49% or higher

MlKl + M2Kz + M3K3 2.8% or less

S1KI + S2K2 + S3K3 3% or less

KI + K2, K3 = l

Ki 0.2 or higher

The objective function

FI = | CIKI + C2Kz + C3K3-49 | = min

F2 = | M2K2 M1K1 + + M3K3 - | = 2.8 min

F3 = | S1K1 + + S3K3 S2K2 2.6 | = min type of K1, K2, K3, respectively for the three mining ore matching proportion;

Cl, C2 and C3 respectively three CaO grade value of the mining area;

M1, M2, M3, respectively the three mining area the content of MgO style;

S1, S2, S3 respectively three mining area of CaC03 standard deviation.

Using the homogenization ore matching model. Formation of mineralized mathematical model calculation in Taiwan respectively file middling grade indexes, USES the microcomputer can quickly calculate the three mining area's annual ore matching ratio K1, K2, K3, and three quality indexes of mining area, the three annual match ore mining area are:

Q1 = K1Q Q2 = K2Q Q3 = K3Q type in Q1, Q2, Q3 respectively three annual match ore mining area;

Q for production plan.

2.3 annual homogenization ore matching planning results

We use the annual homogenization method for the mine ore matching planning, 2004-2008 annual homogenization ore matching planning results are shown in table 3.

The table 3 shows that after the homogenizing ore matching method, the annual mining grade balance, control the quality fluctuation CaC03, standard deviation control in the plus or minus within the range of 3%, waste rock stripping quantity also significantly reduced, in order to ensure the ore quality is stable and make full use of resources into the factory laid a foundation.

3 homogenizing ore matching production planning

3.1 production homogenization ore matching plan on the basis of the data

Ore matching production plan is directly used to guide mine production of short-term production plan, for mine resource utilization, balance to ensure the quality of the mine into the factory has a decisive role. However, because of mine geological exploration degree is relatively thin, the valuation method to calculate the grade of ore block and the actual still has some discrepancy. In order to ensure the accuracy of the ore matching production plan, we in production ore matching for the plan based on production exploration data. Production exploration is given priority to with cannon Kong Yan, change of quality of seam each hole take a sample, small seam quality change every two holes for the same, by chemical analysis, can get the samples of CaO and MgO style grade value.

We will produce the exploration data save production geological database, in case of production when the ore matching, production are: the content of the geological database table number, mining area number, hole size, hole coordinates, CaO, MgO style.

3.2 the homogenization with mine planning method

In order to guarantee the implementation of the annual homogenization ore matching plan and quality balance, the production of ore matching plan to shift production of ore grade is close to where the annual match ore grade as the goal, the homogenization ore matching model is:

Quality constraints:

C2K2 C1K1 + + 49 C3K3 acuity

M1K1 + M2K2 + M3K3 2.8 or less

S1K1 + S2K2 + S3K3 3 or less

K1 + K2, K3 = l

Ki 0.2 or higher

Excavator production constraints Ki qd/q or less

The objective function: FI = | CIKl + C2K2 + C3K3-49 | = min

F2 = | M2K2 M1K1 + + M3K3 - | = 2.8 min

F3 = | SlKI + S2K2 + S3K3 - | = 2.6 min

Type of K1, K2, K3, respectively the three mining ore matching proportion;

C1, C2 and C3 respectively three CaO grade value of the mining area;

M1, M2, M3, respectively the three mining area the content of MgO style;   

S1, S2, S3 respectively = CaC03 standard deviation of three mining area.

Qd rated class for excavator production; Q production plan class.

The grade of each mining area is decided by the location of the excavator, before the start of each shift production, computer operators will date of production, planning, production, the machines excavator location coordinates (X, Y) input computer, the computer according to the hole of the database data, take the search radius of 20 m, calculated for each table excavator on duty the undergroand grade of Ci, Mi and Si. Plug in the homogenization of ore matching model available on duty after the mining area, the optimal proportion of ore matching Ki, calculated according to three Ki by the type of mining ore.

Q1 = K1Q Q2 = K2Q Q3 = K3Q

According to the ore and the distance of each mining area can be calculated for each mining area, the number of send to print out the production car scheduling table at the same time, and direct the production scheduling, in the form of production scheduling table shown in table 4.

4 homogenization extraction production quality management

In order to facilitate management of mine production, the homogenization ore matching scheme into effect, we set up production in mine building quality management center. Each one the center equipped with dedicated microcomputer and printer, vehicular walkie-talkie one, each shovel and cars are equipped with a walkie-talkie, to command and dispatch the whole mine production. Taiwan excavator and the car report to quality control center center assignment at any time, if there are obstacles of the excavator or car, not for production, quality control center, according to the specific circumstances, forklift truck equipped with calculated again, and will inform the production personnel to allocate the results with a walkie-talkie, to ensure the reliability of the mine production quality.  

On duty at the end of the production, will be the actual production ore mining area and the actual test results input computer, calculate the actual production ore on duty and the average quality, and print the production report on duty, the production report can be used as the basis for the next adjust production. Class production report are shown in table 5.

The application effect of 5 homogenization extraction technology

The mine from the beginning of 2004 full implementation of the homogenization extraction technology, through more than a year of application practice proved that the homogenization ore mining technology into the factory for stable quality, make full use of resources has obvious effect in mines, ore quality into the factory in 2004 are shown in table 6.  

The contrast table 6 and table 2 shows that after the homogenizing mining technology in 2004, the year CaO standard deviation is 0.74%, reduced CaC03 standard deviation is 1.32%, than 2003 CaC03 standard deviation 3.42% reduced 1.5 times, the effect is very obvious. From the point of resource utilization, stripping quantity is 15100 t, 2004 more than 2003, 165000 t, 186000 t calculated on stripping cost 6 yuan per ton, saved $990000 a year, visible economic benefit is very remarkable, but save the waste rock field area, is conducive to environmental protection.