RU2520146C1 - Man-made soil obtained by thermal treatment for reclamation of disturbed lands - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: soil-sludge mixture is obtained by thermal treatment and contains a mixture of components obtained by processing wastes in the UZG-1MGZH apparatus for treating oil-contaminated soil in amount of 30-40 wt %, peat 20-35 wt % and sand 20-50 wt %, wherein the mixture of components contains, wt %: vanadium oxide 32.5; carbon 31.4; aluminium oxide 7.5; silicon oxide 7.5; nitrogen oxide 6.8; iron oxide 5.3; hydrogen 4.4; magnesium oxide 1.5; manganese oxide 0.8; lead oxide 0.4; chromium oxide 0.4; zinc oxide 0.4; nitrogen 0.4 and related impurities 0.7.

EFFECT: improving environmental conditions, restoring fertility of oil-contaminated and disturbed lands, higher fertility as a result of enrichment of contaminated soil with oxygen and mineral fertilisers during treatment and reducing oil-contaminated areas.

3 cl, 3 tbl

Description

The invention relates to the protection of the natural environment, in particular to technogenic soil obtained by heat treatment for reclamation of disturbed lands, and is intended for use in the elimination of drill sludge pits, sludge collectors, oil sludge collectors: a) introducing as an inert material into the array of drilling waste when they are neutralization, b) introduction of an empty barn as an aggregate of inert material with complete removal of drilling waste from it, c) application as a component of reclamation layer during the elimination of drill cuttings with the disposal of an array of neutralized or processed drilling waste directly in the barn, d) application as a component of the remediation layer during the elimination of drill cuttings with the disposal of an array of drilling waste after its disposal or processing at a special site, followed by backfilling in liquidated barn; application as a material for the formation of a remediation layer during the remediation of oil-contaminated lands; application as a material for the formation of a remediation layer during the restoration of disturbed lands during the construction of linear structures and site facilities; drawing as a material for fixing the embankment and slopes of infield roads, site facilities at the stage of landscaping, for the formation of turf after sowing reclamation herbs on the territory of licensed subsoil users; drawing on the slopes of quarries of common minerals, ores during open cast mining, overburden dumps to create a fertile soil layer and the formation of a remediation layer; waste shelter and isolation during the reclamation of waste disposal sites; for the construction of embankments of the subgrade and the strengthening of the soil foundations of construction and other sites; during the construction of the subgrade and the construction of reinforced road bases on roads of I-V categories and in II-V road-climatic zones, as well as coatings on roads of IV-V categories; use as a component for the manufacture of mortars.

The prior art soil binder and reclamation composition, including mixture products: water; carbohydrate; protein; iron compounds; strong base and fibrous material (US 7005005, 02/28/2006).

Known soil binder and reclamation composition, suitable for application to bare soil to prevent or slow down soil erosion, and includes mixture products: part of the soil binder, necessary for binding soil particles and containing: water; carbohydrate; protein; iron compounds; and a solid base for increasing the solubility of carbohydrates and proteins in water, making the composition a strongly alkaline pH, at least initially; and a part of the soil reclamation of disturbed lands, including: fibrous material containing at least two different types of fibers, one type of fiber that promotes adhesion of the soil composition, and another type of fiber that contribute to the emergence of new sprouted seeds or plants through the fibrous material in soil (US 7021864, 04/04/2006).

A known composition for the remediation of oiled soils, in which finely dispersed sulfur is used as the oil-oxidizing component, activated sludge or organic and adsorbent is added to intensify the biodegradation process, and non-degassed or insufficiently degassed sulfur can be used as the oil-oxidizing component (RU 2009101698, 07.27.2010).

Disadvantages are insufficient decontamination of oil sludge and other contaminants.

The problem to which the proposed invention is directed is to create a sludge mixture obtained by heat treatment for reclamation of disturbed lands, which would eliminate the above disadvantages.

The technical result of the invention is to improve environmental conditions, restore the productivity of oil-contaminated and disturbed lands, increased fertility as a result of enrichment in the treatment of contaminated land with oxygen and mineral fertilizers, and, accordingly, reduce oil-contaminated sites.

The specified technical result is achieved in a sludge mixture obtained by heat treatment for reclamation of disturbed lands, containing a mixture of components in an amount of 30-40 wt.%, Peat 20-35 wt.% Obtained by processing waste in an installation for the disposal of contaminated soils UZG-1MGZH sand 20-50 wt.%, while the mixture of components contains, wt.%:

Vanadium Oxide - 32.5

Carbon - 31.4

Alumina - 7.5

Silica - 7.5

Nitric oxide - 6.8

Iron oxide - 5.3

Hydrogen - 4.4

Magnesium Oxide - 1.5

Manganese Oxide - 0.8

Lead oxide - 0.4

Chromium oxide - 0.4

Zinc oxide - 0.4

Nitrogen - 0.4

Associated impurities - 0.7.

Associated impurities include proppant containing ceramic balls, cutting of an oil-contaminated layer of earth containing crushed stone, and small wastes of ferrous and non-ferrous metals, namely alloys of metal, steel, aluminum, copper, brass, lead, zinc, chromium.

Wastes obtained through processing at the installation for the utilization of oil-contaminated soils UZG-1MGZH represent waste cuttings and oil sludge and constitute, wt.%:

Oil sludge - 20-25%,

Peat - 30-35%,

Sand - 30-35%

Water - the rest

The sludge mixture is made from the products of the neutralization (roasting) of drilling waste, soils contaminated with oil and oil products, sludge for cleaning pipelines and tanks from oil and oil products pipelines at the installation for the disposal of contaminated soils UZG-1MGZH.

Waste disposal at the UZG-1MGZh installation provides a 99.9% reduction in the concentration of oil products in the oil sludge, the exhaust gas treatment device with an irrigation unit used in the installation minimizes the emission of harmful substances into the atmosphere (purification coefficient for suspended solids is 97.3%, Cleaning efficiency 88.4%).

The unit operates from an alternating current main with a nominal voltage of 380 V, a frequency of 50 Hz and can be used in the field, powered by a generator or on specially equipped sites.

The installation kit includes:

- loading device for supplying oily waste to the disposal chamber;

- high temperature recycling chamber:

- ejector liquid fuel burner GZH-300;

- fuel tank V 400 dm ³ ;

- unloading device;

- exhaust gas treatment device;

- irrigation unit;

- Remote Control;

- electric drive.

Disposal of waste occurs in a high-temperature chamber, which is a rotating drum mounted on track rollers driven by a gear motor.

The temperature required for the disposal of oily waste is created by burning liquid fuel in an ejector liquid fuel burner, as well as by burning organic compounds in neutralized waste.

Fuel is supplied to the burner by gravity from the fuel tank.

Neutralized waste enters the high-temperature chamber from the storage hopper using a conveyor.

The installation is mounted on a frame having an adjustment device for changing the angle of inclination of the drum along its axis.

The neutralized material is discharged into a removable hopper.

Flue gas treatment is carried out in a Cyclone type plant (9) with an irrigation unit.

Starting the installation, bringing it to operating mode and stopping is done from the control panel.

The sludge mixture is prepared at a stationary site directly in the area of liquidation of the drill sludge barn, sludge collector or at a temporary special equipped site.

Neutralized and thermally processed waste of drill cuttings (BS) and oil sludge (NS) after their processing is an inert, environmentally friendly technogenic soil. According to the environmental hazard class, the resulting soil is classified as a substance not higher than hazard class IV.

Physico-mechanical characteristics of the sludge mixture obtained by heat treatment for the restoration of disturbed lands

Table 1 The properties Options Test methods in the mound in the barn Humidity% from 20 to 40 from 30 to 50 GOST 5180 Soil density, kg / m3 from 1600 to 2000 from 1400 to 1600 GOST 5180 The density of dry soil, kg / m3 from 1450 to 1750 from 1250 to 1500 GOST 5180 The strength of the soil shear resistance, kgf / mm ² > 0.005 - GOST 12248 Soil compaction coefficient 0.80-0.90 - GOST 5180

Physico-mechanical properties of the resulting sludge mixture are determined for two conditions:

- in the embankment after being removed from the combustion chamber of the installation, in a loosened state with a view to its further use as soil used as building material;

- at the site of preparation of the mixture obtained after mixing the thermally neutralized waste in the form of annealing products with the addition of the calculated amount of peat in the loosened state for the purpose of its further use for remediation purposes.

The effect of neutralization during the processing of NS and BS and the preparation of a sludge mixture is achieved through the physicochemical method of neutralizing waste by burning in a chamber with a burner at the UZG-1MGZH unit at a temperature of 800 to 900 ° C, the optimal mode is from 600 to 700 ° C .

In the combustion chamber of a thermo-destruction installation, under the influence of a high combustion temperature, complex compounds decompose into the simplest components. Due to this, the content of harmful substances in the exhaust gases is minimized. At the same time, almost complete waste combustion occurs in the installation - the residue in the form of ash makes up 3-5% of the initial waste mass, depending on the composition of the waste.

The oil content in the combusted waste when using the UZG-1MGZH installation is about 3%.

The sludge mixture obtained by heat treatment for the restoration of disturbed lands contains the mixture of components in the amount of 30-40 wt.%, Peat 20-35 wt.% And sand 20-50 wt. Obtained by processing waste in the installation for the treatment of oil-contaminated soils UZG-1MGZH .%, while the mixture of components contains, wt.%:

Vanadium Oxide - 32.5

Carbon - 31.4

Alumina - 7.5

Silica - 7.5

Nitric oxide - 6.8

Iron oxide - 5.3

Hydrogen - 4.4

Magnesium Oxide - 1.5

Manganese Oxide - 0.8

Lead oxide - 0.4

Chromium oxide - 0.4

Zinc oxide - 0.4

Nitrogen - 0.4

Associated impurities - 0.7, which include proppant containing ceramic balls, cutting of an oil-contaminated layer of earth containing crushed stone, and small wastes of ferrous and non-ferrous metals, namely alloys of metals of steel, aluminum, copper, brass, lead, zinc, chromium.

Wastes obtained through processing at the installation for the utilization of oil-contaminated soils UZG-1MGZH represent waste cuttings and oil sludge and constitute, wt.%:

Oil sludge - 20-25%

Peat - 30-35%

Sand - 30-35%

Water - the rest

The operation of the installation through the use of the second stage of purification of exhaust gases can significantly reduce emissions of harmful substances compared with conventional open burning. The purpose of the second stage is to reduce the content of oxides and dioxides of sulfur and nitrogen in the exhaust gases of the plant during processing of soils with a high content of sulfur compounds in the residues of oil and oil products.

The following types of waste can be disposed of in the installation:

- drill cuttings;

- spent drilling fluid;

- oil sludge;

- oiled soil and grass;

- waste oil and air filters;

- oiled rags and sawdust;

- wood of suitable sizes;

- waste oil-containing sorbents;

- oil-contaminated sand (from spills);

- oily waste;

- other combustible materials.

According to GOST 25100 Soils. The classification of waste neutralized and processed in this way can be attributed to the class of industrial soils (dispersed or frozen depending on temperature according to table 2) with various structural bonds formed as a result of human activities (production activities).

table 2  Division of industrial soils by temperature Variety of soils Ground temperature t, ° C Dispersed > 0 Frozen <0

Upon completion of the waste treatment at the installation, soil is produced for the remediation direction of use by mechanical mixing with inert material (peat, sand).

Table 3 The range of the main components of the soil Name of the main components Content in technogenic soil,% of volume (ratio) Priming 70-100 (0.70-1.00) Air dry peat 20-30 (0.20-0.30)

The sludge mixture is a homogeneous, soil-like mixture of loose consistency, depending on the moisture content of the added feedstock - peat, sand.

The humidity of the freshly prepared technogenic soil-slurry mixture for the remediation direction should be within 20-50%. In the process of production and storage of the mixture with stirring and exposure to air for 1 to 30 days, the moisture leveling in the embankment of the mixture is equalized, the industrial soil acquires a loose or viscous-plastic consistency. Immediately before laying, the moisture content of the technogenic soil should be brought to values close to optimal, depending on the direction of use of the technogenic soil during compaction, i.e. from 25 to 30% when carrying out reclamation works and from 13 to 20% when using it in construction.

Composition of BS. During the drilling process, up to 60-70% of water, 25-35% of sludge (cuttings), 5-6% of oil, 0.5% of bentonite and 0.5% of various additives, ensuring optimal operation of the drilling rig, can accumulate in the drill cuttings barn installation. After clarification and pumping out of the liquid phase, the solid phase remaining in the barn - BS is the raw material for thermal neutralization.

When preparing a BS for neutralization, the following physical characteristics should be determined (including in the field):

- density - in the range of 1.5-1.85 kg / m ³ (according to the standard design, 1.5 kg / m ^{3 was} taken for calculations);

- humidity - in the range of 30-60%;

- the content of petroleum products is up to 15% (without additional making inert material), more than 15% (calculated making of inert material is required).

The polluting properties and the polluting potential of drilling waste (in a broad sense - BS, drilling waste water, drilling mud waste) for environmental components are caused by the chemicals and materials contained in them.

Among the chemical elements present in the BS, oxygen, hydrogen, aluminum, silicon, carbon, iron, calcium, magnesium, manganese, sodium, potassium, chlorine, bromine, iodine predominate.

The initial BS should be a fluid-plastic pasty mass having a dark gray color with a metallic tint, oily to the touch and a mild, but characteristic specific smell of oil.

Granulometric composition of BS particles in the range of 200-300 microns. This explains the low waterproofing property of BS, which is explained by the passage of small particles of bentonite under the influence of hydraulic pressure between large particles of rock.

By chemical indicators BS is a colloidal solution of particles of clay, sand, chemicals and oil in water. The pH usually corresponds to an alkaline environment and ranges from 8.5 to 10.5.

Oil sludge - wastes from oil production, oil preparation and transportation processes obtained during the cleaning of tank farms of oil pumping stations, which are a difficult to separate mixture of oil products boiling over a wide temperature range, include water, fur. impurities - clay, sand, iron sulfides and more. Intervals of boiling 80% of the mass from 216 to 350 ° C. The water content is 18% of the mass, the content of sand, clay and iron sulfide is 10% of the mass. The oil sludge taken from the tank is a black gelatinous paste, which, when heated to 57 ° C, passes into an easily flowing liquid at a density of 0.854 g / cm ³ .

NS in sludge collectors and trap oils in reservoirs, regardless of the sources of formation, over time, settle and are divided into three layers:

- the top layer is low-water oil with a relatively low mass content of solids from 0.5% (for trap oils) to 1.5% (for barn oils);

- the middle layer is a finely divided emulsion of a complex type (“direct” and “reverse”) with a mass content of water up to 70-80% and mechanical impurities from 1.5 to 15.0%. The middle layer is usually small in volume. Water and mechanical impurities in it can increase monotonically from top to bottom, can be randomly distributed in volume, and can be distributed almost uniformly;

- bottom, bottom layer - consists of 70% of the solid phase, impregnated with oil to (5-10%) and water up to 25%; the oil content is relatively constant, the amount of solids increases with depth. In this case, the liquid phase is a persistent oil-water emulsion.

Peat for the preparation of the sludge mixture should preferably be used air-dry, dried in natural conditions to equilibrium moisture at the cooking site and corresponding to the technical parameters in accordance with GOST R 51661.3 Peat for soil improvement. GOST R 51661.4 Neutralized peat. Specifications or GOST R 52067. Peat for the production of nutrient soils. Technical conditions

Humidity of air-dry peat (mass fraction of moisture) before using it in a mixture should not exceed 65%.

According to GOST 25100 Soils. Classification for the preparation of the sludge mixture should be used mainly air-dry peat with a degree of decomposition of peat Da _p - from 20 to 35% (slightly decomposed and medium decomposed varieties, respectively). In terms of ash content, when choosing raw materials, preference is given to high-ash peat with an indicator D _as - from 25 to 30 CU

The use of peat in the composition of the sludge mixture leads to sorption, binding of toxic substances contained in drill cuttings, and thereby prevents their migration into the environment. The presence of peat in the prepared soil plays the role of an organogenic substrate that provides optimal conditions for germination of ameliorant plants used at the biological stage of reclamation during sowing, planting them directly in technogenic soil.

Sand for dilution of oil-saturated BSh or NSh must comply with GOST 25100 Soils. Classification. Sand for dilution of oil-saturated BS or NS is introduced into the raw materials before neutralization when the amount of oil products in it is more than 15% in the calculated amount according to the PPR.

When choosing a source of sand, preference is given to coarse fractions of river sands. It is possible to use uniform sand.

Sand - incoherent mineral soil, in which the mass of particles smaller than 2 mm is more than 50% (plasticity coefficient 1 _p = 0). The plasticity number I is the difference in humidity corresponding to two soil conditions: at the yield strength w and at the rolling-out boundary w. Values w _L and w _p according to GOST 5180. Soils. Laboratory methods for determining physical characteristics. The yield index I is the ratio of the difference in humidity corresponding to two soil conditions: natural w and at the rolling boundary w, to the plasticity number.

The sludge mixture, depending on the direction of use, is divided into 2 types:

I - for remediation purposes;

II - for the construction of embankments of the subgrade and the strengthening of the soil foundations of construction sites and for mortars.

III - The feedstock for obtaining the soil is:

- BS is not higher than hazard class III;

- NS is not higher than hazard class III.

When the content in the feedstock for thermal disposal of petroleum products is from 16% to 25%, sand can be used to reduce them according to GOST 25100 Soils. The classification added by mixing into the loading chamber. In cases where the contamination of raw materials exceeds 25%, it is recommended to use sawdust or a sorbent with a high degree of sorption on petroleum products to bring the soil contamination to the appropriate proportion before loading it into the combustion chamber of the installation.

Example 1

For neutralization, 20 wt.% Oil sludge, sand 30 wt.%, Peat 30 wt.% Are loaded into the drive at the UZG-1MGZh installation, and 20 wt.% Water is added, while the full load of the drive hopper is 6 cubic meters. m. Thermal firing of the loaded mixture occurs within 1 hour at a temperature of 800 degrees. The output is a mixture of components in an amount of 40 wt.%, Peat 20 wt.% And sand 50 wt.%, While the mixture of components contains, wt.%:

Vanadium Oxide - 32.5

Carbon - 31.4

Alumina - 7.5

Silica - 7.5

Nitric oxide - 6.8

Iron oxide - 5.3

Hydrogen - 4.4

Magnesium Oxide - 1.5

Manganese Oxide - 0.8

Lead oxide - 0.4

Chromium oxide - 0.4

Zinc oxide - 0.4

Nitrogen - 0.4

Associated impurities - 0.7.

The sludge mixture, which is obtained as a result of heat treatment, belongs to hazard class 4.

This sludge mixture can be used, for example, for the reclamation of sludge pits, adjacent disturbed lands and oil-contaminated lands, dumping roadsides.

When cement, dolomite flour, water are added to this mixture, the resulting composition can be used for laying 1 layer during the construction of roads.

Example 2

For neutralization, oil sludge of 25 wt.%, Sand of 30 wt.%, Peat of 35 wt.% Are added to the drive at the UZG-1MGZh installation, and 10 wt.% Of water is added, while the full load of the drive hopper is 6 cubic meters. m. Thermal firing of the loaded mixture occurs within 1 hour at a temperature of 850 degrees. The output is a mixture of components in an amount of 30 wt.%, Peat 20 wt.% And sand 50 wt.%, While the mixture of components contains, wt.%:

Vanadium Oxide - 32.5

Carbon - 31.4

Alumina - 7.5

Silica - 7.5

Nitric oxide - 6.8

Iron oxide - 5.3

Hydrogen - 4.4

Magnesium Oxide - 1.5

Manganese Oxide - 0.8

Lead oxide - 0.4

Chromium oxide - 0.4

Zinc oxide - 0.4

Nitrogen - 0.4

Associated impurities - 0.7.

The sludge mixture, which is obtained as a result of heat treatment, belongs to hazard class 4.

This sludge mixture can be used, for example, for the reclamation of sludge pits, adjacent disturbed lands and oil-contaminated lands, dumping roadsides.

When cement, dolomite flour, water are added to this mixture, the resulting composition can be used for laying 1 layer during the construction of roads.

Example 2

For neutralization, 23 wt.% Oil sludge, 35 wt.% Sand, peat 33 wt.% Are loaded into the drive at the UZG-1MGZh installation, and 9 wt.% Water is added, while the full load of the drive hopper is 6 cubic meters. m. Thermal firing of the loaded mixture occurs within 1 hour at a temperature of 900 degrees. The output is a mixture of components in an amount of 30 wt.%, Peat 20 wt.% And sand 50 wt.%, While the mixture of components contains, wt.%:

Vanadium Oxide - 32.5

Carbon - 31.4

Alumina - 7.5

Silica - 7.5

Nitric oxide - 6.8

Iron oxide - 5.3

Hydrogen - 4.4

Magnesium Oxide - 1.5

Manganese Oxide - 0.8

Lead oxide - 0.4

Chromium oxide - 0.4

Zinc oxide - 0.4

Nitrogen - 0.4

Associated impurities - 0.7.

The sludge mixture, which is obtained as a result of heat treatment, belongs to hazard class 4.

This sludge mixture can be used, for example, for the reclamation of sludge pits, adjacent disturbed lands and oil-contaminated lands, dumping roadsides.

When cement, dolomite flour, water are added to this mixture, the resulting composition can be used for laying 1 layer during the construction of roads.

Claims (3)

1. A sludge mixture obtained by heat treatment for the restoration of disturbed lands, characterized in that it contains a mixture of components in an amount of 30-40 wt.%, Peat 20-35 wt. and sand 20-50 wt.%, while the mixture of components contains, wt.%:
Vanadium Oxide - 32.5
Carbon - 31.4
Alumina - 7.5
Silica - 7.5
Nitric oxide - 6.8
Iron oxide - 5.3
Hydrogen - 4.4
Magnesium Oxide - 1.5
Manganese Oxide - 0.8
Lead oxide - 0.4
Chromium oxide - 0.4
Zinc oxide - 0.4
Nitrogen - 0.4
Associated impurities - 0.7. 2. The mixture according to claim 1, characterized in that the accompanying impurities include proppant containing ceramic balls, a cut of the oil-contaminated layer of earth containing crushed stone, and small wastes of ferrous and non-ferrous metals: alloys of steel, aluminum, copper, brass, lead, zinc chrome. 3. The mixture according to claim 1, characterized in that the waste obtained through processing at the installation for the utilization of oil-contaminated soils UZG-1MGZH represents waste cuttings and oil sludge and comprise, wt.%:
Oil sludge - 20-25%
Peat - 30-35%
Sand - 30-35%
Water is the rest.