Ore Crushing Plant Upgrading

DS(customer’s mine name in short) copper concentrator has encountered problems such as easy plugging of screen surface and heavy screen funnel, low screening efficiency of vibrating screen, frequent maintenance of some equipment, coarse particle size of crushed products, etc. The technical transformation is needed to influence the smooth operation of the production.

JXSC provides Ore Crushers and grinders globally, includes cone crusher, jaw crusher, hammer crusher, roll crusher, ball mill, etc.

1 Ore crushing process and equipment

In the concentrator, the hardness of the ore is 8 ~ 10, the grinding power index is 14 ~ 15 kWh/t, the moisture content is 3%, and the loose density is 1. 69t/m 3, Density 2. 7tm3.
The rock crushing system is mainly equipped with a vibrating feeder, 16 sets of conveyor belts, and 6 sets of heavy-duty double-deck vibrating screens (pre-screening, heavy screening), 17 single-layer vibrating screens (check and screen, single screen), 4 medium crushing Simons cone crushers and 8 fine crushing Simons cone crushers.

The coarse crushing equipment is three 54 mm*74 mm cycle crushers. The coarse ore is transported to coarse ore heap by three Iron plate feeders. The stone crushing section is responsible for the medium and fine crushing operations of the ore. This process strengthens the pre-screening before the medium crushing and eliminates the adverse effects of the sticky wet powder ore on the ore crushing operations.

A new cone crusher is used to reduce the particle size of the crushed product, and the metal crushing efficiency is improved by automatically controlling the power of the crusher and filling the ore as much as possible, to ensure the particle size P80 of broken mineral products meet the requirements of grinding operation, then improve the grinding efficiency.

2 Existing problems of ore crushing plant

More water flow, easy plugging of screen surface and heavy screen hopper, low efficiency of vibrating sieving, serious aging of Simmons cone, insufficient production capacity, frequent overhauling, affecting production, high system operation rate and coarse grain size of the broken product.

3 Improvement steps

The technical transformation of ore crushing technology includes the adjustment and optimization of technical parameters of existing crushing equipment, the improvement of screening equipment, the improvement of screening efficiency and the reduction of final crushing product granularity. During the transformation of the crushing system, the maximum and minimum feed and discharge parameters of each crushing equipment should be considered, and the transport capacity of the conveyor belt should be considered comprehensively to ensure the normal operation of crushing system.

3.1 Drainage device installation

Installation of connecting flume under the coarse ore heap and at the outlet of the vibrating bucket will lead the accumulated water out, and will lead the water from the high building to the sewage pipe, so that the flow water is greatly reduced, thus improving the screening efficiency and reducing the equipment failure rate.

3.2 Vibrating screen upgrade

3.2.1 Add Weight screen
Adding the original 2 heavy sieves to 3 sieves, reducing the working load of medium crushing, appropriately enlarging the size of the sieve to 12 am *25 mm, and increasing the product yield efficiency 8% to about 13%; gradually replaced the original single screen with the advanced two-stage screen to improve the stability of the inspection screening operation and to provide the guarantee for balanced stable and efficient organization of production.
3.2.2 Screen surface upgrade
Chang the rubber screen mesh into the rubber steel wire screen mesh, to extend the service life of the screen Mesh, the drop of large pieces of ore will be reduced, and the opening form of the screen Mesh be changed from the original straight tube type to the trumpet type, thus reducing the probability of ore blocking the Screen Mesh. The opening ratio of the screen was increased from 37% to 42%, thus increasing the effective use area of the vibrating screen and the screening efficiency from 71% to 75%.
3.2.3 Screen frame support spring upgrade
The original screen frame supporting spring is a rubber spring with an amplitude of 2.0 am, which is easy to be sheared and compressed, poor in oil resistance and light resistance, and easy to be aged. After replacing the high-strength and large-diameter steel spring, the amplitude is increased to 6.5 mm, the service life is prolonged, the bearing capacity is strengthened, the screening speed is accelerated, and the screening efficiency is improved.

3.3 Replace cone crusher

Before 2000 years ago, there were 4 middle-crushing Simons cone crushers, # ~ 4#, and 8 fine-crushing Simons cone crushers, 1# ~ 8#. From 2000 to 2004, four high-efficiency H8000 mm hydraulic cone crushers were introduced to replace 1 #, 2 # medium-crushing Simons cone crushers and 1#, 2 # fine-crushing Simons Cone Crushers. In 2009,2 Metso MP800 MM cone crushers were introduced to replace 1# and 2# Fine Simmons cone crushers to solve the problem of insufficient fine crushing capacity In 2012, 2 METSO MP800 mm cone crushers were introduced to replace 3 # and 4 # Medium Simons cone crushers, and in 2016,2 Metso MP800 MM cone crushers were introduced to replace 1 # and 2 # medium crushing H8000 hydraulic cone crushers solve the problem of hydraulic cone crusher can not automatically adjust the ore discharge size.

In 2016, four Metso MP800 mm cone crushers were adopted, although the capacity and efficiency of the crushers were improved, the final crushing product particle size P80 still did not reduce. In order to solve this problem, a new type of XT750 liner board is developed, which increases the width of parallel band of liner board from 25 mm to 30 MM, prolongs the time of ore remaining in parallel band, increases the times of ore being broken and impacted in crushing zone, and increases the fine particle content in ore discharge Reducing the particle size of the final product of crushing. At the same time, the thickness of lining board is increased by 25%, and the manganese content of the material is increased from 14% to 16%, which can solve the problems of the lining board such as serious wear and tear in the later period, easy to plug up the bucket, increased energy consumption, uneven crushing and lower crushing efficiency, and prolong the service life of the lining board.

3.4 Feed hopper upgrade

The feeding hopper can not feeding ore uniformly, the ore is scattered in the cone crushing chamber, the ore cannot be crowded, the crushing efficiency is low, and the size of the discharging ore is coarse. By adding an 80 mm*1000 mm central funnel to the ore feeder and setting a 900 mm concave ore separator above the moving cone, the ore feeder is lowered through the central funnel and dropped vertically to the Ore Feeder Evenly distributed in the cone crushing cavity, crushing cavity feeding uniform, smooth running current, reduce loop jump, to achieve full ore.

4. Improvement effect

(1) Increase crushing capacity. The cone crusher has been reformed several times, and the capacity of the ore crushing system has been improved remarkably. The problem of the insufficient capacity of the crushing system has been solved. The annual capacity of the crushing system has increased from 24.237 million tons in 2013 to 24.499 million tons in 2016.
(2) Through the technical transformation of the drainage device, the pre-screening and screening vibrating screen, the type of the medium-fine cone crusher is changed, and the production management is strengthened, so the production capacity of the crushing process is improved to a certain extent The potential of the rock ore crushing equipment is brought into full play, the running rate of the equipment is reduced, the equipment is convenient for maintenance, and the particle size of the final crushing product is reduced to P808.5 mm, thus creating favorable conditions for the efficient production of the grinding operation The utility model has the advantages of energy saving, consumption reduction and labor intensity reduction.