Conventional autogenous mill and large-diameter autogenous / semi-autogenous mill feed and discharge minerals from cylinder center. The impacts produced by falling minerals are counteracted by the ore pulp buoyancy, so the grinding efficiency is reduced. Simultaneously, the grinding-stripping force among minerals is increased due to ore pulps.
Targeting at structural flaws of conventional autogenous mill, Xinhai Co. Ltd invents the ultra fine laminating autogenous mill. Minerals are fed in via the middle part of one side of cylinder, while end products are forcibly discharged out from the other side of cylinder via grate by centrifugal force and ore pulp pressure
(1) Considering that there is ore pulp in the ultra fine laminating autogenous mill, minerals fall speedily and is free from ore pulp buoyancy, so the impact is big enough to cause more fissures inside minerals and to extend fissures.
(2) Since there are innumerable inherent fissures in minerals, the laminating-crushing effects and grinding-stripping effects are remarkably reinforced.
(3) When mineral pulps and granules are spirally moved up by the rotating cylinder, they are free of ore pulp effects, so mineral pulp edges and mineral granules are grinded and impacted with each other, repeatedly and directly. As a result, grinding effects are way superior to conventional autogenous mills
(4) Since minerals and water are fed in at one side of ultra fine laminating autogenous mill and end products are discharged out at the other side, the discharging efficiency of eligible products is notably boosted.
(5) The discharging grates are arrayed along the discharging end rim, so grates are consistently situated beneath the discharging end when cylinder revolves in continuity. With the special grate, discharging areas are increased and over grinding phenomena are precluded.
(6) The conventional autogenous mill is plagued by low filling rate which has huge and negative influence on processing capacity. The ultra fine laminating autogenous mill has end products discharged from its lower part and is impervious to “overly stuffed” problem. The increase of filling rate can enormously enhances impacting and grinding force, which greatly improves processing capacity.
(7) Since minerals are not subject to ore pulp buoyancy, the impacting force is very huge and can be transferred into laminating force which can generates more new and accelerating laminating force, so the impacting force is utilized to the utmost.
(8) Since minerals are free of ore pulp buoyancy, mineral pulp edges and mineral granules are grinded and impacted with other repeatedly and directly. The grinding-stripping power generated by mill is utilized to greatest extent.
(1) The ore pulp agitation of conventional self-suction or air-inflation flotation cell is accomplished by impellers driven by shaft which has huge power and energy consumption.
(2) Conventional flotation cells produce bubbles with relatively big size and relatively small specific surface area.
(3) The dispersion effect is less desirable
(4) Conventional self-suction or air-inflation flotation cells use shaft to drive impellers so that minerals are prevented from settling. Consequently, the floating distance and time of ore pulps are limited.
(1) The pressured and lifting air is used to agitate ore pulps, which enable flotation cell to save the dynamics that are needed to finish agitation and to notably reduce energy consumption.
(2) The height of flotation cell is huge; ore pulps must go through damping devices; there is no dead angel inside the flotation cell; mineral granules, air and reagents are quickly blended; specific surface of air and reagents is huge, etc. These features prolong the floating time and improve floating effects.
(3) Air is in the form of microbubble which has huge specific surface area and improves air utilization ratio.
(4) Reagents are atomized and subsequently supplied, so the specific surface area is huge and the utilization ration is high and reagent consumption is reduced.
(1) Highly energy saving
(2) Low reagent consumption
(3) Remarkable flotation index
(4) The utilization of air and reagent is high
(5) The selection is easy and large scale equipment is available
(6) Outstandingly abrasion and corrosion resistant
(7) Low maintenance and operation expenditure
(8) Low total cost of ownership and less floor space
Xinhai tailing dry discharge system-----which is composed of concentrating dewatering hydrocyclone, efficient deep-multiple-cone thickener and efficient frequent dewatering screen----has features like the lowest total cost of ownership, the lowest energy consumption, the lowest production expenditure and the widest particle size. Suppose the working days of a year is 330, Xinhai tailing dry discharge system can reduce the production expenditure by 3.75～6.25 million (RMB). Suppose the concentration is 30%, the water recovery rate is above 75% and 2,300,000 m³ water can be saved. Suppose the water price is RMB1.5/ m³, RMB 3,450,000 is saved. Within one year, two aspects can save RMB 6,050,000～8,550,000 which is enough to recover the investment.
The process chart of Xinhai tailing dry discharge system consisting of concentrating dewatering hydrocyclone, efficient deep-multiple-cone thickener and efficient frequent dewatering screen is as follows:
Xinhai Abrasive Rubber Company patents and manufactures XC Ⅱ dewatering concentrating hydrocyclone which is equipped with fishtail device and siphon device. The siphon device can adjust the underflow concentration at the range of 70～75%. When the fishtail device and the siphon device are set, the underflow concentration can be kept constant.
When XC Ⅱ dewatering concentrating hydrocyclone is utilized for tailing discharge, it can keep underflow concentration constant, which slashes enormously the investment of subsequent equipments which are requested to discharge tailings. As a result, the tailing dry discharge is converted into an economically feasible investment which requires less capital input and provides lucrative retribution
After being dewatered and concentrated by XC Ⅱ dewatering concentrating hydrocyclone, small amount of mineral overflow is carried to thickener for further concentration. After that, underflow from hydrocyclone and thickener are both sent to efficient frequent dewatering screen for dewatering and filtration.
(1) The design of big angled cone increases the compressing area where ore pulps can be incessantly compress so as to enhance the underflow concentration.
(2) The design of multiple cones can reduce considerably the cell height and change the compressing areas to boost underflow concentration
(3) The inclined plate increases the thickener settlement area, prevents mineral granules from floating up, enhances the undercurrent concentration and makes overflow water clearer.
(4) The collecting tray is added to feeding center, which makes ore pulps uniformly fall and averts ore pulps from splashing.
(5) The heterotype overflow weir rectifies the partial suctions caused by out-of-level overflow weir.
(6) The degassing cell adopts more advanced and rational structure which improves notably the degassing effects.
Efficient deep-multiple cone thickener can further concentrate mineral overflow (mainly water, mud, fine granules) discharged by XC Ⅱ dewatering concentrating hydrocyclone. Since efficient deep-multiple cone thickener has bigger settling area and compressing area, higher underflow concentration and processing capacity can be accomplished, in spite of the finer particle size and lower concentration.
In terms of design, efficient frequent dewatering screen has many special and unique technologies. The main component of screen deck can deflect horizontally, while the bear part of screen deck and main deck constitute the upward angle.
The design of sieve pore gives priority to the water permeability. With a special multiple frequency, the highly concentrating ore pulps vibrate at the area comprising of back-side plate and upward screen deck. These two previous features reduce the occurrence of mineral granule passing through screen and improve dewatering efficiency.
Concentrating dewatering hydrocyclone, efficient deep-multiple-cone thickener and efficient frequent dewatering screen deploy their advantages and comprise the unique tailing dry discharge system.
More importantly, the tailing dry discharge system reduces tremendously the equipment and construction investment, the operation expenditure and the management cost, so its superiority can be fully exploited.
Since water recovered from tailing can be utilized by beneficiation, this feature carries special weight in water-deficient areas.