Mine site oil sands processing

Abstract

A process line comprising a combination of mobile and relocatable equipment units is provided at an oil sand mine site. The process line may comprise: a mobile shovel; a mobile bin and double roll crusher; a relocatable conveyor belt extending along the mine face; a relocatable slurry preparation assembly, such as a secondary crusher and jet pump; a pipeline; and a relocatable desanding circuit of separators. The process line conducts the following steps: mining the oil sand; crushing it to conveyable size; conveying it to a slurry preparation location; further crushing it to slurrying size and mixing it with heated water to produce a pumpable, aerated oil sand slurry; transporting and conditioning the slurry in the pipeline; desanding it to produce a product comprising bitumen and water and tailings; depositing tailings in a retention facility; and removing the product from the mine site in a pipeline.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a system, located at a mine site, for mining oil sand, slurrying it and desanding the slurry to produce a pipelineable stream of bitumen, fines and water. BACKGROUND OF THE INVENTION [0002] Oil sand from the Fort McMurray region of Alberta has now been commercially surface mined and processed for about 40 years, to extract and recover the contained bitumen. [0003] The initial technique used can broadly be described as follows: [0004] excavating oil sand; [0005] crushing the as-mined oil sand, which contains large lumps and rocks, in stages, to a size which can be slurried and pumped; [0006] mixing the crushed oil sand with heated water and, optionally, caustic or other process aids, to produce a slurry. In the course of mixing and subsequent pipelining, lumps are ablated, bitumen is liberated from the oil sand and is dispersed into the water phase, air bubbles are entrained and bitumen droplets coalesce and are aerated (...

AI Technical Summary

Benefits of technology

[0037] In one preferred feature of this embodiment of the process line, a lengthy first conveyor means, extending along the mine face, permits the slurry preparation means to remain stationary for a period of time, while coupling it for oil sand supply with the mobile and advancing excavating and sizing means.

[0047] It is a feature of the desanding circuit that subjecting separator underflow to secondary separation improves the probability of recovering contained bitumen.

[0049] In a preferred embodiment, a plurality of such process lines are employed at the same mine site. As a consequence it is possible to transfer oil sand ore or slurry between process lines to cope with upsets or equipment repairs.

Problems solved by technology

Some of these factors are: The oil sand is erosive and tacky and the throughput of oil sand is large.

Therefore, periodic upsets along the processing line can create problems both upstream and downstream.

However, the conveyors, often stretching for miles, were expensive and difficult to operate.

However, the trucks constitute a significant portion of material handling cost and the distance they must travel becomes greater as the mine face moves away from the mixer tower.

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