Mining Machinery Grinding Gold Rod Mill

What Are These Machines and How Do They Work? 

A Ball Mill grinds material by rotating a cylinder with steel grinding balls, causing the balls to fall back into the cylinder and onto the material to be ground. The rotation is usually between 4 to 20 revolutions per minute, depending upon the diameter of the mill. The larger the diameter, the slower the rotation. If the peripheral speed of the mill is too great, it begins to act like a centrifuge and the balls do not fall back, but stay on the perimeter of the mill.

The point where the mill becomes a centrifuge is called the "Critical Speed", and ball mills usually operate at 65% to 75% of the critical speed.

Ball Mills are generally used to grind material 1/4 inch and finer, down to the particle size of 20 to 75 microns. To achieve a reasonable efficiency with ball mills, they must be operated in a closed system, with oversize material continuously being recalculated back into the mill to be reduced. Various classifiers, such as screens, spiral classifiers, cyclones and air classifiers are used for classifying the discharge from ball mills.

This formula calculates the critical speed of any ball mill. Most ball mills operate most efficiently between 65% and 75% of their critical speed.

Types:

Mill could be sorted as following:

As per the grinding media: ball mill, rod mill and AG Mill (without grinding media).

As per material discharging mode: wet grid mill, dry grid mill & overflow mill.

As per driving mode: side & central driving. The former is more popular now.

As per driving configuration:

a. Asynchronous motor driving: Asynchronous motor + Reducer + Pinion +Girth gear

b. Synchronous motor driving: Synchronous motor+ Air clutch+ Pinion +Girth gear

c. Asynchronous motor + reducer + diaphragm coupling

Structure of Ball mill: 

The machine is composed of feeding part, discharging part, turning part and driving part (reducer, small driving gear, electric motor and electric control). 

The quill shaft adopts cast steel part and the liner is detachable. The turning gearwheel adopts casting hobbing process and the drum is equipped with wear-resistant liner, which has good wear-resistance. 

Technical parameters:

Luoyang Zhongde Heavy Industries Co., Ltd, whose predecessor was Luoyang Mining Machinery Cement Equipment Factory, was founded in 1959. Over the past 50 years, Zhongde has made significant contribution to the economic development in China. In 1995, it took the lead in changing into the joint stock company, which had brought a rapid development to the company. In 2006, the old factory relocated into the large modern industrial workshop in Luoxin Industrial Park, Luoyang city, the middle of China.

We are a professional manufacturer of mining equipments, such as crusher, mining mill, tube mill, rotary kiln, cooler, rotary dryer, magnetic separator, flotation machine, thickener, etc. Our machines are widely used in the fields of mine, smelting, chemicals, building materials, coal, refractory materials, ceramics, etc. Moreover, technological designs on program, process flow, standard& non-standard parts are also provided from the beginning to the end for clients.

The total area of the three standard heavy-duty industrial workshops covers 70000 square meters. More than 500 sets advanced processing equipments, including 300 sets of high-precision digital control machine tools, large-sized processing equipment and special processing, riveting& installing machines, are introduced to guarantee for product qualityand company development.

In 2010, we have accessed the ISO9001:2008 certification, and in 2012 we have acquired the BVQI certificate. To establish the business with credit and honesty is our management belief all the time.  

Training & Service

Pre-sale services: enthusiasm
We provide you with the prophase plan, process flow design and manufacturer equipment according to your special demand.

Sale services: servant
Send technicians to the jobsite for guiding the installation and adjustment, training operators and finishing the check and accept together with you.

After-sale services: faithfulness
To establish long term friendship, we will regularly pay return visit to customers.
In addition, we provide one-year warrantee to make sure your machine runs consistently. We always keep certain inventory level of spare parts, which means the replacements can be shipped to you right away.

Welcome to visit our company and workshop, we sincerely look forward to cooperating with you. We will provide you with the most suitable products with the reasonable price.