Uranium Removal from Copper Concentrate via Magnetic Separation

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Solution Overview

Problem

Current magnetic separation techniques are inefficient in reducing uranium content in copper concentrates to commercially acceptable levels, as uranium minerals tend to associate with chalcopyrite, leading to high uranium retention in flotation concentrates.

Innovation Solution

Implementing a process that combines wet high-intensity magnetic separation (WHIMS) with flotation circuits to separate uranium from copper concentrates, involving multiple stages of grinding and re-grinding to optimize mineral liberation and subsequent magnetic separation to reduce uranium content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional magnetic separation techniques are used, then the process is simple, but uranium content cannot be reduced to commercially acceptable levels due to association with chalcopyrite

Engineering Contradiction:
Improveuranium removal efficiencyVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The process segments the uranium removal into multiple distinct stages: initial flotation to separate copper minerals, followed by magnetic separation to remove uranium-bearing minerals, and optional re-grinding with additional flotation. This multi-stage segmentation allows each process to target specific mineral associations, achieving commercially acceptable uranium levels that cannot be obtained through single-stage separation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flotation circuit performs preliminary separation of copper minerals from gangue before magnetic separation. This preliminary action liberates uranium-bearing minerals from chalcopyrite associations, making them accessible to subsequent magnetic separation. The preliminary flotation reduces the complexity burden on the magnetic separation stage, allowing it to focus specifically on removing uranium-bearing minerals.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If multiple grinding and separation stages are implemented, then uranium removal efficiency improves, but processing time and operational complexity increase

Engineering Contradiction:
Improveuranium content reductionVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The process maintains continuous operation through closed-circuit configurations where tailings from one stage become feed for the next. The flotation circuit operates continuously with reground material fed back into the system, and magnetic separation continuously processes flotation concentrate. This continuity eliminates idle time between stages and ensures constant progress toward uranium removal, reducing total processing time despite multiple stages.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The process applies partial grinding and separation stages only when necessary to achieve target uranium levels. If initial flotation-magnetic separation achieves acceptable uranium content, additional re-grinding and flotation stages can be omitted. This partial action approach avoids unnecessary processing time while ensuring uranium removal efficiency when required by commercial specifications.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If wet high-intensity magnetic separation is used, then uranium separation improves, but capital cost increases

Engineering Contradiction:
Improveuranium-copper separation selectivityVSAvoidcapital investment cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The process merges wet high-intensity magnetic separation with conventional flotation circuits to achieve uranium-copper separation. By combining these two separation mechanisms, the system leverages the strengths of each: flotation handles bulk copper mineral separation while magnetic separation targets uranium-bearing minerals. This merging allows the use of WHIMS technology without bearing its full capital cost burden alone, as it supplements rather than replaces conventional flotation infrastructure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The process optimizes operational parameters of magnetic separation to achieve effective uranium removal at moderate capital investment. By adjusting magnetic field intensity, feed particle size distribution, and slurry characteristics, the system maximizes separation efficiency within the constraints of available technology. These parameter changes allow effective use of WHIMS without requiring the most expensive high-capacity units, reducing capital cost while maintaining separation selectivity.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The process effectively decreases uranium content in copper concentrates by 46 ppm, achieving higher copper recovery and selectivity, while minimizing waste generation and chemical reagent usage.

Implementation Method 1

magnetic separation with the aim of reducing the content of uranium in a copper concentrate

Methodology Applied
Scientific EffectMagnetic separation: Magnetism

Implementation Method 2

the magnetic susceptibility of minerals as in a function of magnetic field strength

Methodology Applied
Scientific EffectMagnetic susceptibility: Magnetic Field

Implementation Method 3

flotation circuits to separate uranium from copper concentrates

Methodology Applied
Scientific EffectFlotation: Froth Floatation

Data Source

PatentEP2917378B8Process for removing uranium from copper concentrate via magnetic separation
Publication Date: 2019.03.06 VALE SA

AI summary

The present invention describes a process for removing uranium from a copper concentrate by magnetic separation (low and high field) aiming the reduction of the content of uranium in a copper concentrate to commercially acceptable levels.