ALPHA GRINDING MEDIA

composition and areas of application

In the procurement of steel balls, dimensions are of paramount importance. The critical measurement is the diameter, noted in either millimeters or inches.

Surface finish quality Is denoted by degrees; a lower degree signifies a higher precision ball quality. The precision ball’s accuracy stands at 1µ.

Material selection is anotherr vital aspect when choosing the appropriate steel ball. While various steel types are viable, rolling bearing steel and stainless steel are prevalent choices. Stainless steel balls are particularly valued for their excellent resistance to corrosion, such as rust.

Metal balls have a wide array of uses, from spray cans and valves to level indicators and conveyor systems. There are also niche uses where balls may be intentionally non-spherical, serving as weights or mixers. Additionally, steel balls are integral to our ASK ball bearings and rod ends with ball bearings.

Throughout various ore processing and milling operations, including methods like flotation, cyanidation, gravity concentration, and amalgamation, the fundamental objective is to pulverize and grind the ore, typically using a rod mill or ball mill, to free the embedded minerals.

Grinding plays a crucial role in the chemical and process industries as it prepares raw materials for the next phase of treatment.

Nowadays, ores are ground to a much finer size than what crushers can achieve. Over many years, several types of fine grinding mills have been developed, with the ball mill becoming the go-to choice for its simplicity and cost-effectiveness.

An effectively managed ball mill can perform a multitude of tasks. In smaller milling operations where simplicity is paramount, multi-stage crushing isn’t cost-effective, and a single Steel-Head Ball or Rod Mill can process up to 2-inch feed and refine it to the required fineness.

In larger facilities with multiple crushing stages, it’s standard to grind from 1/2-inch down to 8 mesh.

Grinding circuits often require regrinding of concentrates or intermediate products to ultra-fine dimensions to separate closely bound minerals. In such instances, ball mill feed can range from 10 to 100 mesh or finer.

When uniformity in the final product isn’t necessary, a ball mill can run in an open circuit.

However, for a consistent product, it’s vital to operate the mill in a closed circuit with a screen for coarser outputs, or with a classifier for finer outputs.

Generally, it’s preferable to run the mill in closed circuit for increased efficiency and capacity.

Mills utilizing steel rods as the grinding medium are advised when the product needs minimal fines, as rods yield a more uniform output.

Determining the economically viable fineness for grinding a product often requires analysis. In such cases, the 911Equipment Company provides comprehensive testing services to ascertain the correct mill size.

Ball Mill Capacity vs. Rod Mill Capacity

Until recently, many believed that certain grinding mills had superior efficiency and capacity. Now, it’s widely recognized that a ball mill’s performance is directly related to the power input; the maximum power for any ball or rod mill depends on the grinding charge weight, mill speed, and liner design.

The difference in capacities among grinding mills of the same size is because there’s no standard way to designate mill size. For instance, a 5′ x 5′ Ball Mill with a working diameter of 5′ inside the liners has 20 percent more capacity than other ball mills labeled as 5′ x 5′, where the shell’s inner diameter is 5′ but the working diameter is only 4’8″ with the liners installed.

Ball-Rod Mills, based on 4″ liners, show capacity variations as the mill diameter’s 2.6 power, with the 5′ size offering 20 percent increased capacity; the 4′ size, 25 percent; and the 3′ size, 28 percent. This should be considered when calculating the capacity of a Steel-Head Ball-Rod Mill, as it can hold a larger charge and potentially has a higher capacity for a given size when fully charged.

A shorter mill may be used if the grinding issue requires a specific power input, allowing for future capacity expansion or initial cost savings if extra capacity isn’t needed. Ball-Rod Mills have higher capacities than many other types because their diameters are measured inside the liners.

Capacities in Table I are calculated based on specified conditions.

A grate discharge can be advantageous for certain ores, particularly where an excess of fine sizes is harmful.

Design and Functionality

This apparatus consists of various components such as the feeding section, the discharging section, the rotational section, and the driving section, which includes a reducer, a minor drive gear, an electric motor, and electric controls. The spindle is constructed from cast steel and features a removable liner.

The large rotating gearwheel undergoes cast hobbling fabrication, and the barrel is outfitted with a liner that is resistant to wear, ensuring durability. The apparatus operates under stable and trustworthy conditions.

Additionally, there are two types of ball mills available, dry and wet, which can be chosen based on the material being processed and the method of discharge.

Operating Mechanism

The ball mill is a horizontally oriented cylindrical rotating device powered by a rim gearwheel. It comprises two compartments and a grid. Materials enter the first compartment via the feed inlet. Within this compartment, there are progressive liners and corrugated liners, along with steel balls.

The casing’s rotation generates electrical energy, propelling the balls to a certain elevation before they descend due to gravity, exerting a grinding force upon the materials.

Following the initial grinding phase, materials pass through a segregating screen into the second compartment. Here, materials encounter flat liners and steel balls for further grinding. Once the secondary grinding is complete, materials exit through the discharge end, concluding the grinding operation.