Davis Tube Tester

Determining the magnetic content in products obtained from heavy media processes. 

Determining the magnetic content in products obtained from taconite iron ore processes. Determining the magnetic content in ore samples from prospecting programs.The Davis Magnetic Tube Tester consists of an extremely powerful electromagnet which can generate a magnetic field intensity of up to 4,000 gauss, a glass separation tube and a motor driven agitation mechanism. The tube is positioned between the poles of the magnet at an angle of approximately 45 degrees (the angle is adjustable).

During the operation of a small electric motor drives the agitating mechanism that supports the water filled glass tube.

The tube moves forward and backward while it rotates simultaneously. Any magnetic particles present in the product sample inside the tube are collected in the zone of intense magnetism. A vigorous washing action by agitation is applied to these magnetics. Eventually all non magnetics are flushed from the tube. A clean concentrate of magnetics is then available for determining percent. The Tube Tester is not intended to show total iron content of an ore as will chemical analysis. Chemical analysis shows total iron content whether magnetic or nonmagnetic; and thus fails to give a true picture of what can be accomplished by magnetic concentration. The Davis Magnetic Tube Tester will determine magnetic content and it takes only about 10 minutes for an accurate determination.

Standard equipment:

• Governor controlled variable speed motor, 115 VDC
• Variable speed motor, control box, 115 VAC input, 115 VDC output
• Magnet switch
• 10 feet of rubber hose
• 4 squeeze type hose clamps
• 2 stainless steel pans
• 1 rubber hose

1. Attach three inch piece of flexible hose to discharge end of tube. This can be accomplished by use of tape.
2. Clamp discharge end of hose.
3. Fill tube with water so that magnet poles are covered.
4. Turn on magnet.
5. Introduce crushed sample accurately weighed (10 grams in Standard Duty).
6. Wash with water so that entire sample is in slurry.
7. Place rubber stopper in top of tube.
6. Wash with water so that entire sample is in slurry.
7. Place rubber stopper in top of tube.
8. Unclamp discharge hose clamp and regulate steady flow of water through tube.
9. Agitate tube.
10. Allow to agitate at a constant speed until slimes or cloudiness are washed out of the tube. Magnetic material is attracted and held fast in the magnetic zone between the two magnet poles. It is recommended that length of agitation time and speed be recorded so that a standard procedure can be set up if one type of sample is to be constantly tested for quality.
11. Stop agitation.
12. Remove rubber stopper from top of tube.
13. Turn off water.
14. Place clean pan under discharge end of tube.
15. Turn off magnet.
16. Wash magnetics into pan.
17. Dry magnetics.
18. Weigh and determine percentage of magnetics.