DE102007039453A1 - Bitumen extracting method, involves applying two-stage flotation process in single column cell, bringing gas in contact with bituminous pulp, and utilizing base and post-flotation chambers - Google Patents

Abstract

The method involves applying a two-stage flotation process in a single column cell. Gas is injected according to a pneumatic principle. The gas is brought in contact with bituminous pulp contained in a conditioned material mixture. A base flotation chamber (21) and a post-flotation chamber (22) are utilized during the two-stage flotation process, where the chambers are combined into a single column. The gas required for the base chamber is injected outside the cell in the pulp. An independent claim is also included for a system for extracting bitumen from an oil sand-water mixture.

Description

The This invention relates to a process for recovering bitumen from oil sands-water mixtures by flotation of the treated, a bituminous pulp containing material mixtures. Such Material blends are also called "Middlings" designated. In addition, the invention also relates to a system for bitumen extraction from oil sand-water mixtures with a Device for producing a pulp of raw bitumen and with subsequent ones Flotation cells.

Out The bitumen contained in oil sands can be removed by so-called "upgrading". Synthetic crude oil obtained in refineries is processed into fuels. To recover the bitumen So far, essentially two methods have been applied: on the one hand the mining method, in the near-surface oil sand layers to maximum Mined 50 m depth with open pit method and then the bitumen is extracted from the sand. On the other hand, the so-called SAGD (steam assisted gravity drainage) method in which steam passes through a horizontal Drilling is pressed into deeper deposits and by the heat of the steam the bitumen liquefies and being detached from the sand. By a second parallel Bore the formed water / bitumen emulsion to the surface promoted.

One Subprocess in the mining process is the bitumen extraction: At currently practiced in the oil sands industry the oil sand is comminuted into crushers after mining and sifted out large boulders. After that it gets hot Water and steam are made by a slurry so-called "hydrotransport pipelines" is pumped mostly the removal of the bitumen from the Grain of sand through the mechanical agitation, still by discharging is supported by air. At the end of the pipeline will be the Slurry pumped into a huge sedimentation tank (PSV = primary separation vessel), in which three phases form, so-called primary separation. A bitumen foam floats above desired product that is continuously over the Boiler edge drains off. Down the rock and sit down Sand grains off. The third phase in the middle is the water phase ("middlings"), which still a part of the bitumen (about 10%) and suspended matter and contains the finest sand and clay particles. To the bitumen fraction separating the middlings and returning them to the process becomes a multi-level process in the current process Used flotation, so-called secondary flotation or secondary separation.

In In some oil sands extraction plants, the residual pulp becomes secondary flotation with the lowest phase of PSV, the rock and sandhaltig is and still contains bitumen residues, combined and subjecting this mixture to further flotation, so-called tertiary flotation or tertiary separation.

The state of the art for bitumen flotation is in the 1 shown in detail below. At the same time mechanical agitation cells are used, which are subject to high wear on the agitator and therefore often have to be maintained. The maintenance causes high costs and long plant downtime of the entire flotation bank.

since some time become so-called "column cells" for developed the use in the flotation of middlings, in which injected compressed air and water down into a column and the rising air in countercurrent with that in the upper Part of the cell introduced bitumen-containing pulp brought into contact becomes. In addition to higher availability because of lower Wear this technique as a further advantages a higher Allow bitumen yield and a lower mineral content.

From that Based on the object of the invention, an improved method to indicate the treatment of the middlings. This is a suitable facility be created.

The Task is according to the invention by the measures of claim 1. An associated one Plant is the subject of claim 12. Further developments of Method and the associated Appendix are in the subclaims specified.

object The invention is especially for bitumen extraction new flotation process compared to the today at the processing of the middlings used procedures remarkably Offers advantages. In the associated attachment, the principles taken from the ore flotation.

In the context of the invention, it is proposed to use a two-stage flotation cell hitherto used for flotation of Cu / Mo ore for flotation of the middlings obtained in the oil sands extraction process. Such a cell will be in the WO 2006/061265 A1 and WO 2006/069995 A1 described, wherein modifications are made within the scope of the invention.

The trial operation of a known from the copper (Cu) - / molybdenum (Mo) ore processing Flotationszelle for bitumen processing has surprisingly shown that the two-piece construction with a Grundflotationskammer and a Nachflotationskammer, which are combined into a single column, considerable advantages over conventional mechanical or pneumatic cell len offers. This flotation principle reduced the energy and gas requirements as well as drastically reduced the number of cells connected to flotation benches. The reduced number of cells leads to lower investment costs and a lower space requirement in the processing plant. In addition, a much higher yield of Mo-ore was achieved.

By the use of the two-stage flotation principle in the oil sands extraction process Surprisingly, the improvements achieved in ore processing can also be realized in the bitumen production from the middlings and so the investment and operating costs of the oil sands operators be lowered. With the new column cell is the previous replaces multistage flotation, with both the primary as well as the secondary and the tertiary separation of the prior art can be replaced.

Further Details and advantages of the invention will become apparent from the following Description of the figures of exemplary embodiments with reference to FIG Drawing in conjunction with the claims. Show it

1 the principle of a conventional flotation for oil sands-water mixtures with several cells connected to flotation benches,

2 the longitudinal section through a column cell with two-part flotation cell, which can be used for the oil sands flotation,

3 a horizontal section through a column cell according to 2 and

4 a flotation bank with column cells according to 2 and associated peripherals.

In the 1 is a plant for the flotation of oil sand-water mixtures known, as used in the prior art Bitumengewinnung from oil sands. It is essential that a number of flotation cells 10 . 10 ' . 10 '' , ... which are constructed essentially identically, are cascaded in series. About flow lines 1 to 7 the individual flotation cells are connected to each other, in such a way that from above the oil sand mixture is filled into the Flotattionszellen, skimmed off the foam resulting from the flotation with the bitumen and the bottom of the remaining residue (so-called "slurry") and a next flotation cell is supplied.

In detail serves in 1 The administration 1 for charging the first flotation cell 10 with the middlings. The administration 2 indicates the routing of the residual material ("slurry") from the flotation cell 10 for charging the second flotation cell 10 ' , About the line 3 the removal of the foam with the bitumen product takes place.

In the flotation cell 10 ' includes lead 4 the discharge of the slurry to the third flotation cell 10 '' and direction 5 the removal of the foam with the bitumen product. The third flotation cell has the same effect 10 '' a line 6 Discharge of the "slurry" and a pipe 7 for the removal of the foam product.

So far, such arrangements are known for use in Rohbitumengewinnung. For example, there are three single flotation cells 10 . 10 ' . 10 '' necessary in the cascade. It can be seen that with separate flotation cells a comparatively high energy requirement and also a high space requirement are necessary.

2 is a pneumatically operated flotation column, as it was specifically proposed in the mining industry as a current development. This involves, in particular, separating, for example, copper / molybdenum ores using an air / water mixture.

In detail are in the 2 a first larger flotation cell 21 and a second smaller flotation cell 22 represented nested and the housing of a column cell 20 form concentrically arranged tubes. Specifically, there are an enlarged upper part and a narrower lower part, wherein the inner tube is in within the extended upper part and the housing 20 in a Grundflotationskammer 21 and a postflotation chamber 22 share. The postflotation chamber 22 is at the top 23 in the basic flotation chamber 21 , In this case, a not designated in detail foam collecting container is present, which can be designed as a groove and with an annular nozzle 27 equipped to discharge the foam product.

The basic flotation chamber 21 is powered by gas. This gas, preferably air, is injected outside the column cell under pressure in the bitumen-containing Pule, after which the bitumen pulp / gas mixture thus formed in the Grundflotationskammer 21 is injected. It is essential in this arrangement that the Bitumenpulpe- / gas mixture via a laterally on the circumference of the Grundflotationskammer 21 located injector 24 is introduced tangentially, so that in the Grundflotationskammer 21 a vortex flow arises. Flooding creates a foam product containing the bitumen.

The foam product can be carried away with the slurry from the base floatation chamber 21 in the postflotation chamber 22 arrives. In the postflotation chamber 22 is at the bottom of the circumference ventilation 25 present, so that from the residual material also a foam with other bitumen shares is formed. In the postflotation chamber 22 is about the ventilation 25 introduced compressed air from below and flows from the bottom coming residual pulp from the Grundflotationskammer 21 opposite. It is realized a countercurrent principle. This will be in the basic and Nachflotationskammer 22 Gas bubbles of different diameters produced so that the bitumen-containing fine particles are captured by the smaller gas bubbles and transported into the foam. By varying and adjusting the size of the bubbles, the proportion of floated fine particles can be significantly increased and thus the bitumen yield can be increased drastically.

In a construction according to 2 pure water can be externally saturated in front of the flotation cell / reactor with gas at 3 bar with atmospheric oxygen. This prestressed water is advantageously over the radius of the flotation cell 20 sprayed for relaxation in the inner part, so that forms an additional Flotationsteppich.

On the basis of the sectional view of 3 It is clear that by building the column cell with concentric tubes, the oil sand-water mixture through the injector 24 tangential in the Grundflotationskammer 21 is injected. By contrast, the additional gas-saturated water is sprayed centrically along the axis I.

In 4 is shown that a number of flotation columns 20 . 20 ' . 20 '' , ... parallel and / or connected in series a flotation bank 100 form. The peripheral units such as water treatment o. The like. As a common unit 30 for the parallel column cells 20 . 20 ' . 20 '' or the cascaded columns 20 . 20 ''' designed. A column cell 20 forms with the peripheral unit 30 a flotation unit 50 ,

As already mentioned, the construction of such a columnar flotation device is known from US Pat WO 2006/069995 A1 known. Essential in the present context are the specific modifications with respect to the periphery, which now make the device known per se applicable to bituminous pulps. Such an application is not trivial, since due to the viscosity of the bitumen specific flow conditions exist. Therefore, the nozzles and other means of introducing air and the geometry of the chambers must be adapted to the conditions of bitumen flotation in order to optimize flow conditions, the size distribution of the gas bubbles and the residence time of the bitumen in the cell.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2006/061265 A1 [0010]
• WO 2006/069995 A1 [0010, 0029]

Claims (23)

A process for the production of bitumen from oil sand-water mixtures by flotation of the recycled, containing a bituminous pulp material mixtures, characterized in that for the flotation process in a single cell, a two-stage flotation is applied, wherein the gas injected according to a pneumatic principle and with the Pulp is brought into contact. Method according to claim 1, characterized in that that in the two-part flotation process a Grundflotationskammer and a postflotation chamber leading to a single column are used together. Method according to claim 2, characterized in that that needed for the Grundflotationskammer Gas outside the column cell in the bituminous Pulp is injected and the bitumen pulp / gas mixture in the Grundflotationskammer is injected. Method according to claim 3, characterized that injecting the bitumen pulp gas mixture into the Grundflotationskammer takes place tangentially, so that a vortex flow he follows. Method according to claim 2, characterized in that in the post-flotation chamber, the compressed gas from below is introduced and coming from above bituminous pulp, the flows out of the Grundflotationskammer, counterflows. Method according to claim 2, characterized in that that in the base and Nachflotationskammer gas bubbles with different Diameters are generated. Method according to claim 2, characterized in that that in the Nachflotationszelle smaller gas bubbles than in the Grundflotationskammer be generated. Method according to claim 2, characterized in that that pure water externally in front of the flotation cell at elevated Pressure is saturated with gas and this prestressed water over the radius of the flotation cell for relaxation in the postflotation chamber is sprayed, so that an additional Flotation carpet forms. Method according to claim 8, characterized in that that the increased pressure in the range 1-15 bar abs. is preferably in the range 2-5 bar abs. Method according to one of claims 1 to 9, characterized in that it is the gas used is about air. Method according to one of claims 1 to 9, characterized in that it is the gas used is nitrogen. Plant for the extraction of bitumen from oil-sand-water mixtures, comprising a device for producing a pulp of raw bitumen and subsequent flotation cells, wherein a base flotation chamber ( 21 ) and a postflotation chamber ( 22 ) into a single pillar ( 20 ) are combined. Plant according to claim 12, characterized in that in each case a column cell ( 20 ) with the associated periphery ( 30 ) a complete flotation cell ( 50 ). Plant according to claim 13, characterized in that several flotation cells ( 20 . 20 ' . 20 '' , ...) are present for parallel or serial operation and that a group of flotation cells ( 20 . 20 ' . 20 '' , ...) one flotation bank each ( 100 ) form. Plant according to claim 14, characterized in that a common aggregate ( 30 ) the periphery for the flotation bank ( 100 ). Installation according to one of claims 12 to 14, characterized in that by the structure of the columns ( 20 ) with Grundflotationskammer ( 21 ) and postflotation chamber ( 22 ) and funds ( 24 . 25 )) for the independent generation of gas bubbles the energy or gas demand for the flotation cells ( 50 ) Flotation Bank ( 100 ) is minimized. Installation according to one of claims 12 to 14, characterized in that by building the columns ( 20 ) with Grundflotationskammer ( 21 ) and postflotation chamber ( 22 ) and funds ( 24 . 25 )) for independent generation of gas bubbles the space required for the flotation cells ( 50 ) or flotation bank ( 100 ) is minimized. Installation according to one of claims 12 to 14, characterized in that by building the columns ( 20 ) with Grundflotationskammer ( 21 ) and postflotation chamber ( 22 ) and the means ( 24 . 25 ) for the independent generation of gas bubbles, the yield of bitumen is maximized Installation according to one of claims 12 to 14, characterized in that by building the columns ( 20 ) with Grundflotationskammer ( 20 ) and postflotation chamber ( 22 ) and the means ( 24 . 25 )) for independent generation of gas bubbles, the purity of the bitumen is maximized. Plant according to one of claims 12 to 15, which is for replacing the tertiary multistage flotation on is executed. Plant according to one of claims 12 to 15, which replace the secondary multistage flotation is executed. Plant according to one of claims 12 to 15, which performed to replace the primary separation is. Plant according to one of claims 20 to 22, which are the primary, secondary and tertiary Separation replaced.