CA2455623A1

CA2455623A1 - Four stage counter current inclined plate separator and cyclone circuit

Info

Publication number: CA2455623A1
Application number: CA 2455623
Authority: CA
Inventors: Joy Romero; Ken Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-01-21
Filing date: 2004-01-21
Publication date: 2005-07-21

Description

1 "FOUR STAGE COUNTER CURRENT INCLINED PLATE SEPARATOR and

2 CYCLONE CIRCUIT"

3

4 FIELD OF THE INVENTION
The present invention relates to a circuit for cleaning bitumen froth by reducing 6 the concentrations of contained water and solids contaminants.

9 For many years now, bitumen has been recovered from oil sand using a water-based extraction and air flotation technique. More particularly:
11 ~ the as-mined oil sand is mixed with heated water to produce a slurry 12 containing entrained air bubbles; and 13 ~ contained bitumen is recovered from the slurry in the form of a froth, by 14 flotation.
The froth invariably contains varying concentrations of water and particulate 16 solids contaminants. A typical froth might comprise:
17 bitumen - 60 % by wt.
18 water - 30 % by wt.
19 solids - 10 % by wt.
It is necessary to "clean" the froth by removing as much of the water and solids as 21 one can feasibly manage, to prepare it for downstream upgrading.
22 The present invention is directed to providing a circuit for cleaning bitumen froth.

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2 Figure 1 is a schematic flow diagram of the circuit.

Having reference to Figure 1, a circuit 1 for cleaning bitumen froth 2 is provided.
6 In the first stage of the circuit 1:
7 ~ bitumen froth 2 is pumped into the feed inlet 3 of a conventional primary 8 inclined plate separator ("IPS") 4;
9 ~ overflow 5 from a secondary IPS 6 is recycled and is combined with the froth 2 fed to the primary IPS 4; and 11 ~ fresh light hydrocarbon diluent (e.g. naphtha) 7 is pumped and is combined 12 with the bitumen froth 2 and overflow 5 that are fed to the primary IPS 4;
13 ~ whereby a diluentlbitumen ratio in the order of .65 - .75 is maintained in the 14 mixture processed by the IPS 4.
By recycling secondary IPS overflow S, the bitumen froth density is reduced, enhancing 16 separation in the primary IPS 4. The primary IPS 4 functions to gravity separate water 17 and solids from diluted bitumen. Typically, the IPS 4 contains parallel inclined plates 18 spaced about 38 mm apart and angled at 55°. The overflow 8 from the primary IPS 4 19 constitutes the circuit product. Typically it contains 55 - 58 wt. %
bitumen, 1.0 - 2.0 wt.
% water, 0.5 - 1 wt. % solids with the remainder being diluent.

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1 Carrying on now with describing the second stage of the circuit 1:
2 ~ The underflow 9 from the primary IPS 4 is pumped into the feed inlet 10 of 3 the secondary IPS 6 ;
4 ~ Fresh diluent 11 is also pumped to the feed inlet 10 and is combined with the primary underflow 9; and 6 ~ the overflow 12 from a primary scavenger cyclone 13 is pumped to the 7 secondary IPS inlet 10 and is combined with the underflow 9 and diluent 11;
8 ~ whereby a diluent/bitumen ratio in the order of 39 - 1.5 is maintained in the 9 mixture processed by the secondary IPS 6 .
The secondary IPS 6 functions to recover residual bitumen from the mixture fed 11 to it.
12 By recycling the secondary IPS overflow 5 to the primary IPS 4, bitumen lost 13 with the primary underflow 9 may be recovered on the second pass through the primary 14 IPS 4.
1 S In the third stage of the circuit 1:
16 ~ the underflow 14 from the secondary IPS 6 is pumped into the inlet 15 of the 17 primary scavenger cyclone 13;
18 ~ overflow 16 from a secondary scavenger cyclone 17 is recycled to the inlet 15 19 of the primary scavenger cyclone 13;
~ fresh diluent 18 is also pumped to the inlet 15 and is combined with the 21 secondary IPS underflow 14 and secondary scavenger cyclone overflow 16 ;
22 and {E4136545.DOC;1 }

1 ~ the primary scavenger cyclone overflow 12 is recycled to the secondary IPS
2 inlet 10.
3 The increased separation force in the primary and secondary scavenger cyclones 4 (13 and 17 respectively) scavenges the remaining bitumen by forcing the small diluted bitumen droplets to the cyclone overflows (12 and 16) where it can eventually be 6 recovered as product from the first stage IPS 4. The increased force also removes more 7 fine solids, sending them to tailings.
8 In the fourth stage of the circuit 1:
9 ~ the underflow 19 from the primary scavenger cyclone 13 is pumped into the inlet 20 of the secondary scavenger cyclone 17;
11 ~ the overflow 16 from the secondary cyclone 17 is recycled to the primary 12 cyclone 13 , as previously described; and 13 ~ the underflow 21 from the secondary cyclone 17 is discarded as tails.
14 In summary, the circuit operates countercurrently and provides two stages of IPS's 1 S and two stages of cyclones in series. Fresh diluent is supplied to each of the IPS's and the 16 secondary cyclone to mix with the bitumen increasing the difference in specific gravity 17 between the water and diluted bitumen to allow the bitumen to have a greater chance of 18 being recovered. The scavenger cyclones in series are used to increased the force 19 available to separate the diluted bitumen, water and fine solids.
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