A Brief Overview of Recycling and

Recovery in the Precious Metals Industry

Dr. Robert T. Jacobsen, vice president

Sabin metal corporation

Scottsville, NY

Primary: The Mines, Mills, & Smelters

Feedstocks: Ores

Sinks: Refineries on or off site

Products: Alloys, Concentrates

Sources: Mines

Primary: The Mines, Mills, & Smelters

Flowchart

Mine > Mill > Smelter > Refinery

Secondary: PM Recycling & Recovery

(The High Class Junk Men)

Feedstocks:

Manufacturing Scraps,

Slags, Spent Materials,

Obsolete, Worn Out, or Surplus

Devices or Parts

Secondary: The High Class Junk Men

Sources:

Electronics, Photo, Petroleum

Chemical, Pharmaceutical, Food,

Polymer, Glass, Aircraft, Mining,

Fertilizer, Nitric Acid,

Medical, Plating,

and other Industries

plus

Military and Post-consumer

Scrap and “Waste”

Secondary: The High Class Junk Men

Products:

Sweeps, Concentrates,

Bullion, Fine Metal and Salts

plus

Residues, e.g

Slags, Refractories, Sludges

Secondary: The High Class Junk Men

Sinks:

User Manufacturers,

Primary PM Plants,

Other Secondary Plants,

In House Refineries

Secondary: The High Class Junk Men

Flowchart

Main Differences: Primary vs Secondary

Collection

Valuation Method

Grade

Scale

Secondary PM Industry Processes

Much the same as Primary Industry

Crushing /Grinding

Ball Mills

Wet Dry

Crushers

Jaw, Cone

Hammer

Secondary PM Industry Processes

Secondary PM Industry Processes

Thermal Reduction

Roasting

Indirect Fired Kilns

Direct Fired Kilns

Box Kilns

Rotary Kilns

Secondary PM Industry Processes

Pyro-metallurgical

SmeltingRotary

Crucible

Fossil Fuel

Induction

Submerged Arc

Plasma Arc

Secondary PM Industry Processes

Hydro-metallurgicalClassical Dissolve & Precipitate

Cyanide Strip

Acid/Base Digestion

Solvent Extraction

Ion Exchange

Liquid Chromatography

Secondary PM Industry Processes

Physical SeparationsGravity

Froth Flotation

Magnetic

Flotation Cell

Wilfley Table

Secondary PM Assay Laboratory

Secondary PM Industry

Environmental Aspects

Central Characteristic of Secondary PM Industry

Therefore

Sampling and Analysis!

Customers wish to be PAID(either metal or money)

Almost always

transaction cannot wait for turnout

Secondary Recycler Must Determine

to the Best of His Ability the Amount

of Precious Metal Contained in the

Feed Stock significant

processing!

Before

Thereforethe Secondary Precious Metals Industry

Often Incurs More Expense for

Sampling and Analysis

Than for the Actual Recovery /Refining

Process

Secondary PM Industry

Assay Laboratory

The usual responsibilities for any mine or mill:

Production Control

Quality Assurance

BUT ALSO

SETTLEMENT ASSAYS

Which carry right down to the

Bottom Line

Sampling or Assay Errors

Can be Disastrous:

If too high, refiner pays out more than he has and

Fails!

If too low, refiner loses his customer and

Fails!

Solution Sampling

Aqueous

Molten

Trier’s tube not the best

Dry Sampling

V Blender

Dry Sampling

Blending not the best

What is an Auto Sampler?

>A device for extracting a small representative

sample from a relatively large lot of material for

the purpose of evaluating the composition of

the entire lot.

>The material must be in a free flowing state,

either liquid or free flowing particulate mass.

What is an Auto Sampler?

>A device for extracting a small representative

sample from a relatively large lot of material for

the purpose of evaluating the composition of

the entire lot.

>The material must be in a free flowing state,

either liquid or free flowing particulate mass.

>The material must be made to move in a

steady stream past or through the device.

> Sizes of auto samplers vary

enormously!!

Laboratory Auto-sampler

Medium Auto-sampler

Catalyst Sampler

(Quality Handling Systems Pty Ltd)

Fundamentals of Fair Auto-Samplers

>Full Stream Equi-volumetric Cuts

>Properly sized Extraction Device; e.g. 10:1

>Many cuts or “Increments”

>All of the Material in Either Sample or Reject

>Large enough sample size

>Easily Cleaned

Full Stream Linear Cutter

© Copyright 2008, CSIRO Australia

Particle Size Vs. Sample Size

Assumptions:

>Truckload of Bowling Balls: 20,000 kg.

>10 % Glass, 90 % Plastic, 8 kg. each

>Large Well Designed Bowling Ball Sampler

Determine the Percentage of Glass in the Mixture

How Far to Split the lot Before Crushing:

2,000 kg. ?

200 kg. ?

20 kg. ?

Often Ignored in Our Industry !

Particle Size Vs. Sample Size

If We Split to 200 kg. and Crush it All:

Can We Expect Accuracy to +/- 2% ?

>>>>>>>>NO !<<<<<<<<

We Assumed 10 % Glass

10 % of 200 kg. = 20 kg.

But the Balls Weigh 8 kg. Each

Therefore There Should be 2.5 Balls

Impossible!

The best we can do is +/20% !

Safe (+/- 1%) Sample Size for typical Pt on alumina reforming catalyst

Thank YouThank You !