Understanding The Process And Language Of Mechanical Screeners

Posted on: 14 July 2015

During the early days of the Gold Rush miners could not even have imagined the vibratory screening equipment that is on the market today. They made due with very simple tools such as their pan, pick, and shovel. As the process continued to grow, the tools became more refined. Just as ancient miners had their own types of tools, they also had their own language. Both the methods of screening, as well as the terminology of screening have changed over the years. If you are interested in gold mining, or any other type of mining activities, and you are planning on using vibratory screeners, you need to understand how they work, as well as the language you will be using. 

How Mechanical Screeners Work

Prospectors of long ago, had to shake their mining pans by hand to shift through the materials their pans contained. This is no longer the case. When you use mechanical screeners all of the shaking is done for you. There are two basic types of mechanical screeners even though these come in a wide variety of models. These models can be found in all shapes and sizes. These types are:

  • Flat Screeners - A flat screener normally has one or more large perforated screens, which are usually positioned at an angle. When in operation, this screen which is driven by a motor. The screen vibrates as well as moves back and forth. Once the materials are deposited onto the screen, this action causes the particles of the materials which are smaller than the opening in the screen to fall through the screen. These then fall onto the conveyor belt and are carried to a container, or are collected underneath the screen. Any pieces of material that are larger than the screen perforations will continue to vibrate on top of the screen until it either falls off the side or exits at the bottom of the screen. These screeners work well with wet or dry materials. 
  • Rotating Screeners - These are also called Trommel screens, and do not use vibrations to separate the particles in the materials. Instead, they use the rotation of the cylinder to introduce the particles to the screens. Once the materials are placed in the horizontal rotating drum, the spinning action of the drum causes the finer particles of materials to be flung through the screens which surround the drums on all sides. These materials are then collected below. These screeners work well with dry materials, but often struggle to work with really wet materials. 

The Language Of Screening

No matter which type of screen you choose to use, you must learn to the language of the industry. This helps with communication between everyone involved.

Scalping - When someone talks to you about scalping, you do have to worry about your hair. Scalping involves cleaning the incoming materials from any foreign bodies. These may include oversized materials, trash, or other organic debris. This is often done prior to placing the first load of materials onto your screener, but may be performed by the screener itself.

Blinding - No matter what type of materials you screen, there will come a time when the particles you are screening will plug the openings in your screen and prevent any other materials from falling through.

Brushing - Once your screens are clogged, or blinded, they will need brushing to remove the lodged materials so that you may continue your operation. You, or the designated person will use a brush to brush over the screen and remove the materials.

Frequency - Is the number of times your vibrating screen goes from its highest point, to the lowest point. In the case of Trommel screens, it is the number of revolutions the screens make in a specific period of time. This number is measured, and expressed in hertz (Hz).

Shaker - Simply refers to your device, or your machine.

These are just a few of the more common terms, there are many more you will hear over the course of time. Mining can be a fun activity, especially now when you have more equipment to assist you.