Did You Build Something Yet Tim???
LET ME know......k? ■
Re: Stationary Grizzly For Small Placer Mine
Dear Mr. Tim Dunk,
You have mentioned material size 15-20% more than 10 inch, and maximum size up to 30 inch. I presume size you are referring is the maximum dimension of lump in any direction.
Such grizzly (grid) is provided on two considerations. First consideration is relating to safety i.e. one would try to keep the opening around 300 mm x 300 mm. This will prevent somebody falling into the hopper.
Now, you already have a lump size of nearly 30 inch and therefore, you will require grid opening corresponding to this dimension. So if you provide 30 inch opening everything will pass through and it will not require any attendance / breakage of the lumps lying on the grid. Often such oversize happens to be very small in percentage and user prefers that keep the grid opening smaller which will permit majority of the material to pass through and at the same time give better protection to the equipment. Then they keep laborer to manually break / push the lumps stuck on the grid. Such thing is common for wagon tippler hopper dealing with coal, where coal supplier has committed maximum lump size of 300 mm but sometimes wagons contains very small proportion of lump size more than this. By providing smaller opening one also saves in the sizing of the downward equipment.
You have mentioned the 24 inch wide reciprocating pan feeder and conveyor width 30 inch. This does not match with your maximum lump size.
Regards,
Ishwar G Mulani.
Author of Book : Engineering Science and Application Design for Belt Conveyors.
Author of Book : Belt Feeder Design and Hopper Bin Silo
Advisor / Consultant for Bulk Material Handling System & Issues.
Pune, India.
Tel.: 0091 (0)20 25871916 ■
Stationary Grizzly for Small Placer Mine
Greetings,
Firstly, thank you for all the knowledge and help you provide. It’s always more inspiring to work with some direction.
I require information for construction of a stationary grizzly. Feeding grizzly with 3yd loader, 8’6” wide bucket. Scalping 15-20% >10”. Oversize can be up to 30”, and is composed of rounded granite and smooth slabs of slate. The alluvial gravel contains clay and considerable moisture. Some of which is excavated from bellow water table. Scalping followed by 24” wide reciprocating pan feeder, onto 30” X 29’ conveyor, and then 26” X 72” vibrating screen deck. 3/8" plate slotted with 3/4” X 4" holes. Bars of 1 3/8” drill steel overlay each column of slot centers.
Any thoughts on dealing with the shallow but wide pieces of slate?
I have ” plate from which I hope to fabricate grizzly bars and tapered caps, and more drill steel for crowning the caps.
If grizzly bars are 10’ or 12’ long, how much taper is required? Maybe this is too long and would require too much taper. Would a step deck benefit this, even though stationary?
If the “step-deck” design were practical, how much of a step would be suitable. Eventually will up-grade to a rubber carrot type scalper/feeder. But need more gold first.
One more question: what slope can I expect to attain with the conveyor given this material? Side idlers are at 16.5 deg.
Cutting torch and welder are ready, and finally most of that wonderful white stuff is gone – Eureka!
Respectfully,
Tim Dunk ■