The solid particles in the slurry are precipitated to the bottom of the container under the action of gravity, and the water moves in the opposite direction. The process of separating the slurry from the clear liquid and the concentrated pulp is called precipitation concentration.
During the sedimentation and concentration process, the movement of the ore particles follows the sedimentation law of the general solid particles in the liquid medium, and starts to move with acceleration for a very short period of time. Later, due to the resistance of the medium, the gravity of the ore particles is gradually balanced, and the ore particles are Gradually tend to move at a constant speed, which is called the final velocity of the settling.
If the sedimentation of the ore during precipitation is regarded as the movement of a single ore in an infinite medium space, and the mechanical resistance between the ore phase and the ore and the wall is neglected, the sedimentation velocity of the ore can be used. The Stokes formula is calculated, namely:
Where VO - the end of sedimentation speed of the ore particles, cm / sec;
x——The shape factor of the ore particles, that is, the ratio of the final velocity of the sedimentation of the ore particles to the final velocity of the spherical body with the same volume and the same weight. The value of this coefficient is roughly the same for different shapes of ore particles: smooth shape 0.52; polygon 0.72; rectangle 0.67; flat shape 0.52;
D——the diameter of the ore, cm;
δ-- mineral grain density, g / cm 3;
⊿ - medium density, g / cm 3 ;
μ - medium viscosity, poise.
In the pulp, the size of the ore particles is not uniform, and the purpose of the precipitation is to lower all the ore particles to obtain a clear liquid. Therefore, it must be calculated according to the final velocity of the minimum particle.
It can be seen from the above formula that the particle size of the ore particles has the greatest influence on the final velocity of the sedimentation because the sedimentation velocity is proportional to the square of the particle size. Therefore, the finer the mineral grains, the slower the sedimentation rate. Therefore, in the sedimentation process, the most difficult to settle is the fine slime. The more mud in the pulp, the more difficult it is to clarify. For colloidal particles having a particle size of 0.1 to 0.001 μm, due to the molecular repulsion, Brownian motion, and electrostatic repulsion of the same-named charged particles, their tendency to settle due to their own weight is balanced, and there is virtually no precipitation. In order to improve the sedimentation of such suspended ore particles, their charge must be eliminated so that the particles combine with each other to become large flocs and clusters. In beneficiation plant, by methods generally added electrolyte, or a gel polymer flocculant surfactant, so that the dispersed particles flocculate and accelerate the settling. [next]
In a continuously operating concentrator, the precipitation process of the slurry in the concentration tank is shown in the figure below.
The slurry to be concentrated first enters the free settling zone B, and the particles in the slurry drop rapidly by their own weight. When settled to compression zone D, the pulp has collected into tightly angled, fibrous sponge-like agglomerate structures. Continue to sink to the concentrated pulp zone E, which creates a tapered surface due to the operation of the squeegee. The slurry is subjected to the pressure of the squeegee to further concentrate the precipitate and then discharged from the discharge port.
When the slurry falls from zone B to zone D, part of the ore particles are blocked by dense ore particles and cannot sink freely, forming a transition zone C between the two zones B and D. Depending on the nature of the pulp, zone C is sometimes thin and sometimes thick. Above the free settling zone is the clarification zone A. In Zone A, clarified water is obtained, which flows out of the overflow tank. In Zone E, concentrated concentrates are available for concentrates; for tailings, waste is discharged.
As the slurry is continuously fed and discharged, there is always a settling zone. In this case, the clarification speed of the slurry is calculated by the sedimentation velocity of the sedimentation zone, and the final concentration of the concentrated product is determined by the residence time of the compression zone of the slurry. When the feeding and discharging speed of the concentrator is constant, the concentration of the concentration determines the concentration of the discharged product, and the height increase causes the product concentration to be relatively increased. However, since the sedimentation speed of the compression zone is small, increasing the height of the concentrator does not greatly increase the product concentration, so the total height of the concentrator currently used in production is generally not more than 3 to 5 meters.
Yangzhou Gemini Vehicle Industry Co., Ltd. has more than 20 years experiences in producing and selling metal body parts of various vehicles. We are specialized manufacturer of Hoods used for HYUNDAI, including ACCENT, ELANTRA, CRETA, SONATA, TUCSON, SANTA, MISTRA, STAREX, I10, ATOS, I30, and H100 PORTER. We own Hydraulic Machines, Punching Machines, Numerical Control cutting Machines, CNC Grinding Machines, Painting and Electrophoresis Coating lines. We provide "Professional Efficient Effective" service to all of our domestic and oversea customers. We are very glad to be contacted by you and hope that we can keep a long-term cooperation on the business of Steel Body Autoparts.
Hoods For HYUNDAI
HYUNDAI Hood,Carbon Fiber Hood HYUNDAI,Used HYUNDAI Hood,HYUNDAI Glass Hood Car
Yangzhou Gemini Vehicle Industrial Co., Ltd , https://www.yzqsap.com