A mining method for reducing the mixing rate of limestone and miscellaneous rocks

Abstract

The invention relates to a mining method for limestone open-pit mines. A mining method and process for reducing the mixing rate of limestone debris, comprising the following steps: Step 1: Operation adjustment basis: Step 2: Operation adjustment method: The beneficial effect of the invention is that after using the method, by controlling the mixing rate of mining debris to ≤2%, the rotary kiln condition is stabilized, the lime output can be increased by 100 tons per day, and the economic benefit of 9.6426 million yuan is created.

Description

Technical Field

[0001] The invention relates to a mining method for a limestone open-pit mine. Background Art

[0002] In the calcination process of large-scale metallurgical lime rotary kiln, the mixing rate of limestone and other rocks in the raw materials seriously affects the stability of the rotary kiln condition.

[0003] In the actual production process, yellow-grey lime blocks were found in the lime at the kiln head of the rotary kiln, the lime powder rate of less than 2mm increased, the powder ash on the cooler grate plate was sticky, the coal powder was not burned completely, and the kiln condition deteriorated. The rotary kiln was forced to reduce production, which seriously affected production efficiency.

[0004] Therefore, whether it is possible to develop a mining method and process that can reduce the mixing rate of limestone debris will be beneficial to improving the output and quality of metallurgical lime. Summary of the invention

[0005] The purpose of the present invention is to provide a tuyere valve plate device in view of the above problems.

[0006] The object of the present invention is achieved by: a mining method and process for reducing the mixing rate of limestone and miscellaneous stones, comprising the following steps:

[0007] Step 1: Operation adjustment basis:

[0008] 1) Adjustments are made based on the grade of the original ore and the trend of the ore body, with the geological grade as a reference;

[0009] 2) Miscellaneous stone determination criteria: CaO+MgO≤8%, MgO8%~10%, SiO23%~4%;

[0010] 3) When the lime at the rotary kiln head is less than 2mm and the lime powder rate is 6% to 8% or continues to increase, operate according to the following standards.

[0011] Step 2: Operation adjustment method:

[0012] 1) When the lime at the kiln head of the rotary kiln is less than 2mm and the lime powder rate is 6% to 8% or continues to rise, adjust the ore unloading position to the emergency ore unloading position and adjust the ore source;

[0013] 2) When the lime powder rate of the rotary kiln head is less than 2mm and has a downward trend and does not exceed 6%, the excavation process will remove the interlayer roof plate to penetrate 0.2-0.3m into the ore layer, and the ore layer bottom plate will be excavated 0.2-0.3m higher than the interlayer. After visually checking that the roof plate is cleanly removed and there is no abnormality in the cross section, the warning piles and small red flags are used on site to identify the mining area and adjust the ore source;

[0014] 3) When the excavation and transportation process feedback shows that the rate of large blocks in the roof interlayer is 10-12% and the roof fluctuation height is 0.5m-1m, adjust the blasting backfill height from 3.5m-4m to 3-2.8m.

[0015] Furthermore, mining technicians will conduct on-site confirmation of the planned mining area, and only after confirming that the roof has been cleanly removed and there are no abnormalities in the cross-section will they give permission to mine.

[0016] The beneficial effect of the present invention is that after using the method, by controlling the mixing rate of mining debris to ≤2%, the kiln condition of the rotary kiln is stabilized, the lime output can be increased by 100 tons per day, and economic benefits of 9.6426 million yuan are created. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings.

[0018] Figure 1 It is a schematic diagram of the mining of K1 and K3 of the present invention.

[0019] Figure 2 This is a schematic diagram of K2 mining in the present invention.

[0020] Among them, 1. 0.2 to 0.3m deep into the ore layer, 2. 0.2 to 0.3m higher than the interlayer. DETAILED DESCRIPTION

[0021] The purpose of the present invention is to stabilize the kiln condition of the rotary kiln, reduce fluctuations, and improve the production and quality of metallurgical lime.

[0022] The present invention aims to provide a mining method and process for reducing the mixing rate of debris in mining, which is characterized by: following the core idea of ​​increasing the limestone recovery rate and reducing the limestone depletion rate, always keeping the rotary kiln condition in a stable state; adjusting the perforation blasting method and the debris removal method in advance according to geological data and the trend changes of the ore body. By adopting the above method, the fluctuation of the rotary kiln condition can be greatly reduced.

[0023] The mining method and process for reducing the mixing rate of limestone and miscellaneous rocks provided by the present invention include the following steps:

[0024] 1. Basis for Operation Adjustment

[0025] 1) Adjustments are made based on the grade of the original ore and the trend of the ore body, with the geological grade used as a reference.

[0026] 2) Criteria for determining miscellaneous stones: CaO+MgO≤8%, MgO>8%, SiO2>3%.

[0027] 3) When the lime at the rotary kiln head is less than 2mm and the lime powder rate is greater than 6% or continues to increase, operate according to the following standards.

[0028] 2. Operation adjustment method

[0029] 1) When the lime at the kiln head of the rotary kiln is less than 2mm and the lime powder rate is greater than 6% or continues to rise, adjust the ore unloading position to the emergency ore unloading position and adjust the ore source;

[0030] 2) When the lime powder rate of the rotary kiln head is less than 2mm and has a downward trend and does not exceed 6%, the excavation process will remove the interlayer roof plate to 0.2m deep into the ore layer, and the ore layer bottom plate will be excavated 0.2m higher than the interlayer. After visual inspection that the roof plate is cleanly removed and there is no abnormality in the cross section, the warning piles and small red flags are used on site to identify the mining area and adjust the ore source;

[0031] 3) When the excavation and transportation process feedback shows that the rate of large blocks in the roof interlayer is ≥10% and the roof fluctuation height is ≥0.5m, the blasting backfill height is adjusted from 3m to 2.8m.

[0032] Benchmark Example

[0033] Firstly, a mining method for reducing the mixing rate of debris in mining is provided.

[0034] The specific steps are as follows:

[0035] (1) The blasting process creates better working conditions for the excavation and transportation process by controlling the roof fluctuation height to ≤0.5m and the roof interlayer large block rate to ≤10%.

[0036] (2) During the excavation and transportation process, the interlayer roof is removed to a depth of 0.2m into the ore layer, and the bottom plate of the ore layer is excavated to a height of 0.2m above the interlayer. After visual inspection shows that the roof has been removed cleanly and there are no abnormalities in the cross section, warning stakes and small red flags are used on site to identify the mining area.

[0037] (3) Strictly implement the mining permit system. Mining technicians shall confirm the planned mining area on site and only permit mining after confirming that the roof has been removed cleanly and there are no abnormalities in the cross section.

[0038] Implementation Cases

[0039] This embodiment firstly takes the change of the raw ore grade and the trend of the ore body as the main basis for operation, and then makes advance operation adjustment according to the change of the lime powder rate of less than 2mm at the kiln head of the rotary kiln.

[0040] The specific steps are as follows:

[0041] 1) When the lime at the kiln head of the rotary kiln is less than 2mm and the lime powder rate is greater than 6% or continues to rise, adjust the ore unloading position to the emergency ore unloading position and adjust the ore source;

[0042] 2) When the lime powder rate of the rotary kiln head is less than 2mm and has a downward trend and does not exceed 6%, the excavation process will remove the interlayer roof plate to 0.2m deep into the ore layer, and the ore layer bottom plate will be excavated 0.2m higher than the interlayer. After visual inspection that the roof plate is cleanly removed and there is no abnormality in the cross section, the warning piles and small red flags are used on site to identify the mining area and adjust the ore source;

[0043] 3) When the excavation and transportation process feedback shows that the roof interlayer block rate is ≥10% and the roof fluctuation height is ≥0.5m, adjust the blasting backfill height from 3m to 2.8m;

[0044] The above embodiments show that after the above operation method is used to replace the original operation based on the results of the next step of detecting miscellaneous stones, the rotary kiln condition is stabilized, the lime production can be increased by 100 tons per day, and an economic benefit of 9.6426 million yuan is created.

[0045] The invention discloses a mining method for reducing the mixing rate of miscellaneous rocks in mining, scientifically follows the core idea of ​​improving the limestone recovery rate and reducing the limestone depletion rate, and always keeps the kiln condition of the rotary kiln in a stable state.

[0046] The above description is only a specific embodiment of the present invention, but the structural features of the protection scope of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are all covered by the patent scope of the present invention.

Claims

1. A mining method for reducing the mixing rate of limestone and miscellaneous rocks, characterized in that: The following steps are involved: Step 1: Operation adjustment basis: 1) Adjustments are made based on the grade of the original ore and the trend of the ore body, with the geological grade as a reference; 2) Miscellaneous stone determination criteria: CaO+MgO≤8%, MgO8%~10%, SiO23%~4%; 3) When the lime at the rotary kiln head is less than 2mm and the lime powder rate is 6% to 8% or continues to increase, operate according to the following standards; Step 2: Operation adjustment method: 1) When the lime at the rotary kiln head is less than 2mm, and the lime powder rate is 6% to 8% or continues to rise, adjust the ore placement to the emergency ore placement and adjust the ore source; 2) When the lime at the kiln head of the rotary kiln is less than 2mm, and the lime powder rate has a downward trend and does not exceed 6%, the excavation process will remove the interlayer roof plate to penetrate 0.2-0.3m into the ore layer, and the ore layer bottom plate will be excavated 0.2-0.3m higher than the interlayer. After visually checking that the roof plate is cleanly removed and there is no abnormality in the cross section, the warning piles and small red flags are used on site to identify the mining area and adjust the ore source; 3) When the excavation and transportation process feedback shows that the rate of large blocks in the roof interlayer is 10-12% and the roof fluctuation height is 0.5m-1m, adjust the blasting backfill height from 3.5m-4m to 3-2.8m.

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