It is the contention of this paper that there remains considerable confusion regarding the mechanisms and benefits of thickened tailings schemes.  This paper will attempt to clarify some of these issues.

The terminology and interpretation of terms like “thickened tailings” and “paste” receive some consideration, in light of some observed contradiction in the industry.

It is also noted that a number of tailings related myths prevail amongst tailings practitioners.  Some of the more prevalent misconceptions will be addressed, including:

• Solids concentration is a good indicator of rheological properties (across different tailings types)
• Thickening can be targeted to be to an “absolute” solids concentration
• Higher levels of thickening result in a better final density in the storage
• The density achieved on a dry beach is the maximum for the storage
• Higher levels of thickening will result in the optimum outcome
• Water recovery at different sites can be compared without allowing for initial solids concentration,
• climate, and storage configuration,
• All methods of beach slope prediction are equally valid.

The subject of tailings beach slope prediction has been approached from a number of directions over the past 40 years.  Various prediction methods have been presented.  Some prediction methods are analytical, with no need for any flume testing.  Others have relied on a deposition test in a flume.  The use of different types of flumes and deposition tests, either for providing validating data or input data, has created a great deal of confusion over what works and what doesn’t, what is relevant and what is not.  There has also been further confusion created by the presentation of the results, with some workers presenting fitted data as predictions.

This paper discusses the mechanism of tailings deposition, with a view to evaluating the applicability of some of the approaches that have been presented.  Various flume types and their relevance to the process are then discussed.  Deposition tests and trials are also discussed in terms of the beach slopes that have been observed.  Finally, some protocols are proposed for making the presentation of data more consistent and transparent.