Research

Zero Waste and Minor Elements Program

Program Leader: Mr Warren Bruckard, CSIRO

In an environment where recycling is becoming more the norm in households around the world, is it not possible to recycle the materials coming from process waste streams? A team within CSRP has been studying these waste streams and looking for alternative uses for these materials. The tailings, residues, slags and fumes produced by the minerals processing industry contain large quantities of valuable materials such as iron, zinc, titania (titanium dioxide), copper and alumina. Can alternative, economical uses ultimately be found for these and other waste stream materials?

Often a barrier to the beneficial use of waste streams is presence of minor elements embedded in materials which can pose a threat to our environment. Therefore safe extraction and containment of theses minor elements was a vital outcome from this program. The early removal of minor elements which can contaminate the final product will result in a higher quality product and enable these toxic components to be concentrated and stabilised.

Producing high-quality products with minimum waste was the general aim of this program – to develop flow sheets for zero waste scenarios for mineral processing operations. This was investigated by looking at and characterising the most prospective waste stream as alternative resources, as well as assessing the feasibility of promising technologies and developing a multi-disciplinary approach.

A long list of potential waste streams covering the entire mineral processing and metal production sector was established through a series of workshops and dialogue with the industry. A methodology was developed and applied for prioritising the various waste streams. The project team in consultation with industry developed a set of selection criteria and applied these to rank various waste streams with respect to techno-economics, environmental, social and political issues as well as the nature of waste. CSRP engaged with industry to gain support for extending the R&D activities to demonstrate the most attractive processing options.

Achievements

Characterisation and prioritisation of large number of waste/byproduct streams from the mineral industry. Conceptual flowsheets for value recovery from some of the byproduct streams. Preliminary flowsheets to separate sulphides from non-sulphides in tailings wastes and to recover potentially valuable products from sulphide tailings streams. Development and application of predictive thermodynamic models of unit processes for improved management of minor elements in smelting processes. Laboratory validation of new flowsheets to separate arsenic from base metals at the beneficiation stage to produce saleable base metal concentrates and low-volume stabilised waste streams.

Impacts

• Removal of so-called "penalty elements" will mean higher prices for Australia's mineral exports. Many mineral and metal manufacturers impose a penalty on ore supplies that exceed certain limits on elements that are either hazardous to humans or the environment, or impact the efficiency of the mineral process, resulting in higher operating costs.
• Control of toxic elements will reduce their emission to atmosphere and waterways thus reducing short-term and longterm impacts on the environment and human health.
• Ensuring that toxic materials are not dispersed in large volume by-product streams will enable more beneficial uses of these by-products and reduce the size of large-scale storage facilities.

Completed Projects

• Control of Minor Elements (2D1)
• Early Flotation of Mineral Components Containing Arsenic (AMIRA P970) (2D9)
• Early Removal and Safe Disposal of Arsenic and Other Minor Elements during Base Metal Processing (89) (2D8)
• Minor Elements in Smelting (AMIRA P671) (2D6)
• Toward Zero Waste (4A1)
• Toward Zero Waste (4A1 Extension)

Contact

Mr Warren Bruckard
CSIRO Process Science and Engineering
p. 03 9545 8566
e. warren.bruckard@csiro.au