Rod Mill & Ball Mill Grinding Circuit

This Rod Mill —Ball Mill grinding team is in operation at a new 500 ton-per-day, base metal, selective flotation mill. Preliminary Grinding Tests Without Charge Mill size and specifications are determined by experienced engineers who study your grinding problem in detail and take into account the effect of grinding on your total milling circuit. Laboratory … Read more

Mill Bearing Strength & Grinding Mill Design

First, let us look at the mill itself. Fig. 1 shows that there are four basic components – The shell, the heads, the ring gear and the trunnions. The heads are usually bolted to the shell. The trunnions are secured to the heads by bolts or made integrally with the head. The ring gear is … Read more

Automatic Grind Control

The “best” control strategy for a given plant is the strategy that most closely fulfills the overall operating objectives. The best strategy will likely not be “optimum” for any given specific goal but rather will involve a series of trade-offs made in consideration of the many factors that influence the operation in any significant way. … Read more

Grindability of Various Ores

During the last few years, one of the great problems in the milling of all ores has been that of grinding. This subject involves not merely the cost of the operation, but also the selection of the proper degree and character of grinding to yield the best metallurgical results on the given ore. Considering the … Read more

Grinding Media Wear Rate Calculation in Ball Mill

In the previous discussion the fact was established that the work done by a ball when it strikes at the end of its parabolic path is proportional to its weight and velocity; then, since the velocity may be considered as constant for all the balls in the mill, the work done by a ball is … Read more

Ball Mill Grinding Theory – Crushing Motion/Action Inside

Testing Plant Equipment: In order to determine, among other things, the operating conditions of the ball-mill when working on this rock, a test mill of about 300 T. daily capacity was erected at Duluth, Minn. The fine-crushing plant contains a Hardinge 8-ft. by 22-in. (2.4-m. by 55.8-cm.) conical mill, a 6- by 27-ft. (1.8 by 8.2-m.) … Read more

Ball Milling

These notes are based on observations made while on a recent trip through the West, for the purpose of studying the practical operation of the ball mill. The writer takes this opportunity to express his thanks for courtesies extended at the many plants visited as well as for the valuable data received. While there are … Read more

Hardinge Conical Mill Capacity

The following conclusions on the work of the Hardinge mill are based on data furnished to the writer by the Hardinge Conical Mill Co. in the form of the mesh cards hereto appended. Energy units (E. U.) and relative mechanical efficiencies (R. M. E.) are computed by the “volume method” of Stadler. Screen apertures used … Read more

Conical Ball Mills VS Chilean Pan Mills

In view of the prominence which the conical mill has attained in the fine-crushing field within the few years since its introduction, the following comparison with its more mature forerunner, the Chilean mill, based on extensive tests, is submitted in the interest of the milling profession. Soon after designing the concentrating plant, the conical Ball mill … Read more

Hardinge Conical Mill – Grinding Efficiency Compared

Nearly every mining and metallurgical engineer will recall his early experience and method of producing step- or stage- reduction in preparing ore-samples for assay, in which he employed idea, step- or stage-reduction simply because it was a self-evident fact that it would be easier to break coarse ore with a hammer than it would be … Read more