FI60852C - OVERFLOWER FOR OIL SHEET FRAON EN BLANDNING AV OLJA OCH VATTEN - Google Patents

Description

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jjSTa 161 (11) UTLÄGGININCSSKRIFT 6 ° o52 C (* 45) Patent granted 13 04 1932 Patent meddelat (51) Kv.ik.Wci.3 C 02 F 1/24 // B 01 D 1? / 02, E 02 B 15/04 ENGLISH —Fl N LAN D (21) P * t «nttlhakemu * - PitwitansAknlng 791165 (22) Hikemlsptlvl— AiwSknlngsdaf 09.0U.79 (23) Alkupftivi —Glttlghettdag 09-0U.79 (41) Tullut | Bllvlt offantllg 10.10.80

Patent and Registration Office ....

m. . , (44) Date of issue and date of publication. -

Patent- och registratyrelaen 'Ansakin utiagd och utkakrutm publican * 31 -12.8l (32) (33) (31) Privilege requested - Begird prtorltet (71) (72) Act Emil Lukkarinen, Ritokalliontie 8-16 C, 00330 Helsinki 33,

FIELD OF THE INVENTION This invention relates to a process for removing oil from a mixture of water and oil by applying foaming in a mineral enrichment technique. (5U) A method for separating oil from a mixture of water and oil.

The following methods are now commonly used to remove oil that has entered water:

The simplest way is to allow the volatile constituents of the oil to evaporate, causing the non-volatile oil fractions to either sink to the bottom of the pool or drift ashore. The removal of the latter depends on mechanical measures. It is clear that this approach is questionable in terms of natural pollution.

The oil rig can be isolated with booms and the oil recovered whenever possible. The method is slow, and the oil can be easily escaped either by sinking or otherwise and often over a wide area.

Evaporation-promoting chemicals can be used to decompose the oil, but it is feared that they will cause at least as much harm as the oil remaining in the water.

The oil is soaked in peat or diatomaceous earth. When both of these substances are porous, they absorb water in addition to oil. When hydrogenated, they form a mass that sinks to the bottom.

The use of pumice has also been proposed for oil recovery, for which it is suitable due to its porous structure. However, obtaining large enough quantities presents difficulties when considering current needs. Despite its structure, the adhesive surface of pumice blocks is unfavorably small.

According to one method, the oil can be pressed to the bottom of the water basin if the oilH

2 60852 A fine, hydrophobic rock powder, such as an iron concentrate, is applied to the surface, and then a gas stream is blown into the mixture. In this case, too, the aim is to press the oil onto the bottom of the basin, where it is a constant source of pollution, if natural conditions are involved.

The oil emulsified in water can be foamed by injecting finely dispersed air into the emulsion, whereby the oil-water emulsion adheres to the surfaces of the air bubbles and rises to the surface of the water. However, the oil in the water does not completely emulsify with water unless it is treated with a special emulsifier chemical and mixed vigorously. This can be difficult in the case of large quantities. It should also be noted that when the oil adsorbs only on the surface of the bubble, it gets back on the water when the bubble breaks.

The present invention is based on the use of a flotation method commonly used in mineral enrichment technology for the removal of oil with the aid of a carrier mineral. In the flotation technique, as is known to those skilled in the art, mineral oil is used. as a non-ionizing collector chemical with a strong tendency to adhere to the mineral surface and make it water repellent or hydrophobic. Through the water-repellent layer, the mineral adheres to the surface of the air bubble and thus foams. When enriching minerals, the foam that rises to the surface of the flotation device is recovered. This method can be applied inversely to the removal of oil into the water, i.e. to the separation of the oil from the aqueous oil mixture. When a finely ground aggregate is mixed with a mixture of oil and water, the oil adheres to the surfaces of the granules of the aggregate, forming a water-repellent layer around the granules. In the case of a non-ionizing collector, rock powder and so on can also be adhered to the layer formed by it.

If low-pressure air is blown under the mass formed simultaneously with the application of the rock powder, the mineral-covered mineral mass adheres to the surfaces of the air bubbles and can be peeled off by means of suitable equipment. If necessary, a small amount of water surface tension reducing agent can be used to harden the foam. These include, but are not limited to, pine oil (Pineoll), polyglycol ethers, triethoxybutane, and many other foams used in flotation technology.

Due to the non-ionization of the oil, the quality of the aggregate is not essential to the flotation process itself, but by using, for example, limestone powder, which is a naturally occurring mineral in a fatty acid-fuel oil emulsion foam, its white color can be easily monitored compared to a dark mineral. When using rich waste, the price of the aggregate consists exclusively of excavation and transportation costs, and in addition it is already ground to suit.

The invention is illustrated by the following examples: 3 60852

Example 1

One liter of water was taken into the dish of a standard laboratory flotation machine, to which 10 g of crude oil and, in successive experiments, 10 g, 50 g and 250 g of fine tailings from the Hitura mine with a grain size of less than 0.3 mm were added. The slurry thus obtained was then mixed by a machine mechanism and a few drops of polyglycol ether were added as a foam. The mixture of rock and oil was then foamed by blowing low pressure air into the apparatus to give the results shown in Table 1.

table 1

Amount of aggregate Amount of oil removed from the original amount of oil remaining in the clarified original oil water g / l of oil% 10 1.1 89 50 0.8 92 250 1.8 82

The result shows that the water can be removed from the water by adding aggregate and using the usual flotation method known from the enrichment technique. It is also seen that the amount of rock powder already weighing the amount of oil has bound 89% of the total amount of oil to be removed by foaming and that increasing the amount of rock powder has not brought about a significant improvement in the amount of oil to be removed.

Example 2

A second series of experiments was performed as described in the previous example, in which the aggregate was finely ground limestone. The results of this series of experiments are shown in Table 2.

Table 2

Amount of aggregate Amount of oil removed from the original amount of oil remaining in the clarified original oil water g / l of oil% 10 0.11 98.9 50 0.11 98.9 250 0.08 99.2

The results of the second experiment show that the limestone powder was even better than the Hitura waste. Already equal to the amount of oil limestone