Re-election
Re-election is a process in which the useful minerals and gangues are separated according to the difference in density, particle size and shape of the minerals, and the useful minerals are relatively enriched. It is widely used because of its traditional economy, simplicity and convenience, and no pollution.
Paving chute made with iron or wooden board. The slot width is 1 meter - 1.5 meters and the length is 2 meters - 3 meters. The head has a uniform plate for distributing the slurry, and the bottom surface of the groove is made of a cotton wool cloth, a blanket, a cotton blanket, a nylon blanket or the like having a rough surface. The slope of the groove surface is 7°-8°, and the angle of the uniform plate is 20°-25°. The gold minerals selected are less than 1 mm in size.
The deposit is made of paving chute, and the pavement is mostly made of coarse sacks or blankets, which are arranged in an orderly manner, flattened at four corners, the groove size is 1800×600×400 (mm), the groove partition plate is 300 mm high, and welded with 4 mm thick steel plate, The material end is provided with a halving plate, and the discharge end is provided with a baffle plate, so that the heavy mineral containing gold is retained and recovered.
The jig is suitable for processing coarse and medium ore, with a lower limit of 0.2 mm to 0.074 mm, preferably 18 mm to 2 mm. The concentration of the ore is generally required to be about 30%. A mine measured a section of mill slurry into the classifier front chute mineral gold grade of 158.61 g / ton - 166.95 g / ton.
In the jigging room with the sieve plate, the vertical alternating periodic water flow under the sieve is added, so that the material layer on the sieve plate is sometimes loosened and sometimes densely populated, because the rise time is greater than the fall time, so loose After the bed is lifted, the fine and heavy particles have sufficient time and space to form a granule and pass through the sieve. After the water tank is collected, it is discharged by the concentrate pipe, and the heavy particles are concentrated to the bottom of the sieve plate, which can be cleaned regularly. It is medium-weight particles, coarse light particles and fine light particles in this order. The laying of the artificial bed stone constitutes the artificial bed layer, which is placed close to the bottom of the sieve plate, and coarse and heavy particles are placed thereon. The iron chain is also used as a artificial bed stone for easy cleaning and no loss.
In addition to the stroke stroke, the jigging operation parameters include the thickness of the bed and the amount of jigging water, the amount of feed and the degree of uniformity. The jigging bed consists of two parts: the natural bed layer and the artificial bed layer. The artificial bed layer is usually composed of steel balls and barite with a density slightly lower than that of heavy minerals. The sorting condition can be artificially adjusted, and the ratio of the two is directly increased. Affect the sorting effect. The thicker the bed, the longer it takes to loosen and stratify, the higher the quality of the product, the lower the minerality, and the thinner the bed, the opposite. When the density difference between the useful component and the gangue mineral is large, the bed layer may be thinner, and the bed layer may be thicker when the density is poor.
The amount of jigging water refers to the water supplied from the sieve to the ore end and the water added under the sieve, which can be regulated by means of a pipe valve. The larger the amount of water on the sieve, the faster the discharge rate of light products, and the greater the treatment volume, but the stratification is incomplete, and the light products are easily mixed into the mineral particles with higher density. The main function of the additional water under the sieve is to enhance the upper flushing flow and make the bed loose for sorting. In a re-selection jig, the natural bed has not yet formed, the artificial bed composed of steel balls and barite is bare, and the sorting effect is extremely poor. After adjusting the water on the sieve to make the natural bed layer 100 mm high, the upper and lower layers are fastened. The slow zigzag jigging curve makes the job recovery rate more than 95%. The jigging to the ore can be controlled by changing the concentration, pump, pipe valve, etc., and those with larger particle size differences should be pre-staged before selection.
In addition to the stroke stroke, the shaker operating parameters include the slope angle, the flushing water, the ore supply, the ore concentration, and the selected particle size. Shaker installation requirements are smooth, there should be no abnormal beating during operation, the longitudinal direction is generally horizontal, and the concentrate end should be 0.5° higher when coarse particles are selected to improve the selection effect; the concentrate end should be 0.5 when the fine mud is selected. °, in order to facilitate the fine grain concentrate to move forward. When the cross slope is increased, the downward sliding effect of the ore is enhanced, and the discharge speed of the tailings is increased, but the zoning of the selected area is narrowed. Generally, when handling coarse-grained materials, the cross-slope should be larger; when handling fine-grained materials, the cross-slope should be smaller. The cross-slope adjustment range of coarse sand, fine sand and slime shaker is 2.5°-4.5°, 1.5°-3.5° and 1°-2° respectively. In addition, the cross slope of the shaker should be matched with the size of the horizontal flow. Generally, when the coarse material is selected or selected, the rinse water is larger. The rinse water concentrate has a high grade but a low recovery rate. The shaking water of the shaker includes two parts of the mineral water and the washing water, and the mineral water is mainly ensured to be the selected concentration, and the flushing water mainly adjusts the fan-shaped zoning of the bed surface.
The amount of ore fed to the shaker should be properly uniform. The coarser the particle size, the larger the amount of ore should be. However, if the amount of ore is too large, the recovery rate will decrease significantly. When the concentration of coarse ore is 20%-30%, the fine grain is 15%-25%. In order to ensure the fluidity of the bed slurry, it is required that the water depth is immersed in the ore particles for stratification. Most of the ore water flows down the tailings belt, and the fine mud metal minerals are also taken away when the fine mud is washed away, so it is necessary to intercept and recycle. The upper limit of the particle size of the shaker is 2 mm - 3 mm, and the lower limit is 0.037 mm. The materials should be graded before being selected, and if necessary, the mud should be removed beforehand. The post operator should closely monitor the bed surface zoning, adjust it at any time, and intercept the product according to the requirements of the sorting index. A rough selection shaker is unclear, and the concentration is large and the stroke is small. The adjustment is made for this purpose, and the end point of the concentrate is marked with red paint. As a result, the enrichment ratio is more than 100, the accuracy is very high, and the sorting effect is extremely high. good.
It refers to the stroke of the plunger strokes after reselection apparatus moving vertically or horizontally maximum distance, in millimeters, attached on a common device reselection start paper and pencil devices vertically or horizontally on the painted strip trajectory average Seek. The distance between the transmission mechanism and the reselection device can be adjusted. The number of times of re-election is the number of movements per minute of the device, in units of times per minute, measured by the constant table. Changing the diameter of the pulley can regulate the stroke.
For coarse-grained materials and thicker beds, it is advisable to use large strokes and small strokes. Fine-grained materials, fine sands and slime are usually used for small strokes and large strokes. A gold mining boat was seriously lost in gold and found that the stroke was too small to be only 30 mm. After the upward adjustment to 75 mm, the recovery rate was 98%.
The Knelson concentrator has a recycling level of 0-6 mm and is commonly used in grinding classification circuits. It is especially suitable for flotation of gold and fine gold, which is difficult to recover.
Solved the problem that the heavy mineral bed is rapidly crushed and there is not enough sorting time and space. The density difference between light and heavy minerals is magnified 60 times in the 60G centrifugal field. Heavy minerals are deposited in the ring ditch, and the light minerals are continuously taken away by the recoil. , after the upper part of the sorting cone enters the tailings pipe and is discharged. When the ring is filled with heavy minerals, the semi-continuous Nielsen concentrator needs to stop feeding for a few minutes, flushing the concentrate out of the ditch and discharging it regularly.
When the slurry is fed to the bottom of the enrichment cone, it is deflected toward the inner side wall of the cone by centrifugal force and moves upward along the inner wall, while the conical water inlet continuously injects a water flow into the cone to fluidize the bed. Under the combined action of centrifugal force and recoil hydraulic force, heavy ore particles such as monomer gold can overcome the radial resistance of water and centrifugal sedimentation or drilling subsidence settles in the concentrate bed. The target minerals are periodically discharged from the machine through the automatic control system to become products. Due to the small centrifugal force, the gangue mineral is difficult to overcome the action of recoil. As a result, the axial flow force and the axial component of the centrifugal force are combined to be discharged into the tailings.
Gold re-election of grinding circuit example 1 The gold ore content of a selected plant is 23.42%, of which the gold content is more than 5%, and the thickness of the grinding after grinding is 65% and -200 mesh 55%. When the particle size is less than 0.8 mm, the inclined groove of the ball mill into the classifier is changed into the paving chute, and the artificial turf slip is welded and welded at the discharge port of the second-stage ball mill.
In addition to adjusting the slurry flow rate in the production, the water is loosened in time. Each shift is slid 2 times, and the 2 sets of slides are alternately cleaned, which does not affect production. After clearing the heavy minerals through the double-diameter vibrating sieve with a double hole diameter of 6×6 (mm) sieve, after removing the large granules, directly select them on the XZY2100×1050 shaker, and pick up the gold in the bed washing area and after the re-election Demagnetization to the slag fine scouring crude gold can be directly smelted after a certain amount. Large pebbles and tailings are all returned to the process.
The selection found that the gold particles in the bed surface washing area are up to 11 mm, which is wheat bran, and has granular, strip-shaped and irregular shapes, mostly 6 mm. The grade of the shaker gold concentrate is 5×104 g/ton—8×104. Gram / ton, the amount of gold selected accounted for 1.2% of the total amount of gold, due to the use of the whole mud cyanide - carbon slurry process, saving 30% liquid sodium cyanide 37.02 kg.
A 250 ton/day plant uses a re-election + flotation process. The coarse minerals after a gravel mill are graded and returned to the sand for 10 mm to 20 mm (opening on a classifier). After the sieved product enters the 6S shaker, the gold content of the gold-accumulated plant is 40%, the cost is increased by 1 yuan per ton, and the recovery rate is 93%.
Example 2 A mine measured a section of mill slurry into the classifier front chute mineral gold grade of 158.61 g / ton - 166.95 g / ton.
A selected plant installed JT2-2 jig re-election gold in the grinding graded loop. The jigging tailings went straight into the classifier under the action of water flow. After the concentrate was put into the pool, the pump was driven into the 6S shaker to realize the re-election process automation. . The jigging screen adopts a rubber sieve plate with a large diameter and a small diameter of 6 mm and 4 mm, and a manual bed stone with a 25 mm steel ball. The artificial bed has a thickness of 75 mm to 80 mm, wherein the steel ball has a height of 400 mm. Millimeter.
This re-election reduced the tailings gold grade by 0.026 g/t, a year-on-year decrease of 11.5%, and the recovery rate increased by 2.03 percentage points. However, the concentrate pump is easy to block, and after the problem of a certain section of the re-election system, the self-flow discharge between the mill and the classifier returns to normal. There is also a standard Val-type diaphragm jig installed in the limited space of the mill discharge and classifier inlet, which has a compact structure and remarkable effect.
The gold in the grading re-selection grinding graded loop, because the mineral particle size is relatively coarse, it is advisable to use large strokes and small strokes, such as minerals below 0.8 mm, with a stroke of 5 mm and a stroke of 210 times/min. The ore water accounts for 20%-30% of the total water consumption, and the water consumption is generally 1.5m3/ton-10m3/ton, with an average of 3m3/ton-5m3/ton. The normal bed is loosely expressed as a bed. The pulsation is loose and smooth, and when inserted by hand, the resistance is not large and it is easy to insert. Check the bed layer, the ore particles are layered according to density, the tailings do not run through the organism, and the concentrate grade and recovery rate are higher. When sorting the raw gold ore to separate the coarse concentrate, the unit screen area is 20 tons/m2. -50 tons/m2 or more.
Example 3: A KC-XD20MS Nielsen sorting process of a section of grinding and grading of 0.012 mm - 0.2 mm medium fine gold is used in a selected plant to uniformly process the concentrate after five or six hundred grams of concentrate. After the tailings pump is driven into the cyclone, the grit is re-grinded to form a closed circuit, and the overflow is stirred and floated. It was found that the recovery rate of gold reached 9.98%- 13.42%, and the gold content of minerals before and after re-election was about 2 g/ton. Comparative industrial experiments found that the process Nielsen re-election + flotation is more than a single flotation, the gold recovery rate is 1.2-1.5 percentage points higher, and the tailings grade is 0.02 g/ton - 0.06 g/ton.
The re-election process of flotation tailings gold is flotation tailings - ∮ 1500 spiral chute + (concentrate) 6S shaker - concentrate bagging (unified sales). The capacity of the spiral chute (∮1500, height 4300, pitch 540) + shaker (6S, 4500 × 1865 × 1560) is about 100t / d.
The capacity of a mine selection plant is 3000t/d, the crushing size is ≤350mm; the grinding grain size is -12mm; the swirling overflow fineness is -200 mesh 35%-50%; the Nelson-shaker recovery rate is 30%-35%; the flotation grade The original ore is 1.6g/t-1.8g/t, the gold concentrate is 35g/t-40g/t, and the tailings are said to be 0.2g/t. The flotation recovery rate is 62%--57%, and the flotation concentrate yield is 4.02%. Tailings re-election of gold concentrate: grade 12g / t - 15g / t, yield 0.3%, weight 10g / t - 12t / d, at least 120g of gold. Including steel and civil engineering total investment of 1 million (equipment of 30,000 yuan per set, because of the much more), the investment recovery period is about 50 days.
The capacity of a mine selection plant is 450t/d. The flotation tailings can be completed by spiral chute (∮1500, high 4300, pitch 540) + shaker (6S, 4500 × 1865×1560) 5+1 sets, and one set is spare. Due to the fineness of the tailings -200 mesh reaches 70--75%, the capacity of the set is about 100t/d. At least 10g of gold is produced on the day. Including steel, valve tube •, box body, fine tail trough, civil construction and other preliminary estimates of 200,000-300,000 yuan, investment recovery period of 80--120 days. Calculated from 20 to 30 / (10 × 250) × 10 -4.
The mine with a capacity of 450t/d was used to sort the flotation tailings with the Nielsen concentrator. The results showed that the grades were close before and after the selection. The cause was the large amount of tailings. The total number of tailings was 1.09t and the grade was selected for 9 days. 46.32g / t, from which 50.49g of gold was selected, indicating that Nielsen's recovery of particulate gold is instantaneous.
Glass Mason Jar,Ball Jars Wide Mouth,Mason Jar Wine Glass,Jelly Jam Mason Jars
XUZHOU NORTH STAR PACKING PRODUCTS CO.,LTD , https://www.nspglassbottle.com