WO2024123281A1 - A concrete comprising dusts and/or ashes obtained from ferrochrome chimneys as a component - Google Patents
A concrete comprising dusts and/or ashes obtained from ferrochrome chimneys as a component Download PDFInfo
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- WO2024123281A1 WO2024123281A1 PCT/TR2023/051205 TR2023051205W WO2024123281A1 WO 2024123281 A1 WO2024123281 A1 WO 2024123281A1 TR 2023051205 W TR2023051205 W TR 2023051205W WO 2024123281 A1 WO2024123281 A1 WO 2024123281A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- ferrochrome
- concrete
- dusts
- chimney
- ashes
- Prior art date
Links
- 229910000604 Ferrochrome Inorganic materials 0.000 title claims abstract description 42
- 239000004567 concrete Substances 0.000 title claims abstract description 38
- 235000002918 Fraxinus excelsior Nutrition 0.000 title claims abstract description 19
- 239000002956 ash Substances 0.000 title claims abstract description 19
- 238000000034 method Methods 0.000 claims description 15
- 239000002994 raw material Substances 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 2
- 238000005266 casting Methods 0.000 claims 2
- 239000008240 homogeneous mixture Substances 0.000 claims 1
- 239000004568 cement Substances 0.000 abstract description 22
- 238000004064 recycling Methods 0.000 abstract description 2
- 238000004519 manufacturing process Methods 0.000 description 22
- 239000002699 waste material Substances 0.000 description 13
- 229910052799 carbon Inorganic materials 0.000 description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 11
- 239000000428 dust Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 11
- 239000011651 chromium Substances 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- 239000002893 slag Substances 0.000 description 8
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 5
- 229910052804 chromium Inorganic materials 0.000 description 5
- 239000000945 filler Substances 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 238000010891 electric arc Methods 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011449 brick Substances 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 239000005431 greenhouse gas Substances 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- 238000003911 water pollution Methods 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 239000004484 Briquette Substances 0.000 description 1
- 229910001021 Ferroalloy Inorganic materials 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000013067 intermediate product Substances 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000010309 melting process Methods 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000000246 remedial effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000010257 thawing Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Abstract
The present invention relates to a concrete comprising dusts and/or ashes obtained from ferrochrome chimney dusts as a component, which are a recycling product that reduces the use of cement in the relevant technical field and provides high strength and heat resistance instead.
Description
DESCRIPTION
A CONCRETE COMPRISING DUSTS AND/OR ASHES OBTAINED FROM FERROCHROME CHIMNEYS AS A COMPONENT
TECHNICAL FIELD
The invention relates to production method for a product of concrete which comprises dusts and/or ashes obtained from low-cost, high-value-added ferrochrome chimneys as a component.
PRIOR ART
The demand for concrete products is increasing rapidly with the increasing population. Cement is an important component in concrete. Cement production is an intensive activity that consumes a lot of resources and energy. Cement industries release large amounts of carbon dioxide and other greenhouse gases, which cause global warming. Cement production and consumption should be reduced in order to reduce greenhouse gases, save energy and protect natural resources.
High carbon ferrochrome contains 60% to 70% chromium by weight or mass and 4% to 6% carbon by weight or mass. For the production of high carbon ferrochrome, a charge material consisting of a chromite ore, a carbon-containing reductant and a slag forming agent of suitable composition is melted in three-phase submerged arc furnaces containing three carbon electrodes. Almost all ferrochrome is produced in the submerged electric arc furnaces. To meet this specification, the alloy requires a chromite ore with a high Cr/Fe ratio (>2). Chromium and iron in chromite ore may form a continuous series of solid solutions under certain heat treatment conditions containing 45-80% chromium. Metallurgical wastes produced as by-products of melting technology are ashes, sludges and slags.
Generally, a chimney is placed 1 .8-2.4 meters above an edge of the submerged arc furnace ladle. Dust and fumes from the melting process are drawn into the chimney by a large volume of the circulating air. The chimney dust formation also increases with the increase in ferrochrome production. Many research activities are ongoing worldwide to recycle and/or use the waste generated during the ferrochrome
production. The research results clearly show that the ferrochrome material found in the chimney dust studied is closely related to the slag-forming materials; therefore, the enrichment techniques can only enrich ferrochrome values to a very limited extent.
The slags and ashes formed in the chimneys during the high-carbon ferrochrome production are generally disposed of as a type of waste categorized thereafter. The use of the cast ferrochrome slag in refractory castable materials reduces product cost and is atmosphere-friendly. This material is used in road construction and brick production, and has recently been tried as a base layer material in the cement industry and in pavements due to its excellent technical properties. In general, slags have a wide range of uses such as briquette and brick making, railway ballast, cement industry, concrete aggregate, asphalt aggregate, filler, insulation and glass production. Slags can also be used to improve the abandoned and acid-treated mine sites. In 2011 , global ferrochrome production was around 8.9 million tons.
The invention of the patent application no. RU2703036 C1 is related to a method developed to improve the environment by using production waste for the production of a concrete mixture processed with low energy costs and thereby, obtaining high- strength, heat-resistant concrete products. The invention consists of 11.1 -12.2% by weight (w/w)of chamotte chimney dust, 13.8-15.4% of a slag in self-degrading ferrochrome chimneys, and in addition to these components, 40-42.0% of an etching solution of the used aluminum alloys, and 30.4-35.1% of a nickel slag.
In the relevant technical field, the materials used for system implementations of the backfill concrete production for use in mines in the present art are known to have disadvantages in terms of preventing environmental pollution, reducing preparation time and cost of the waste recycled raw materials used, failing to achieve the strength provided to the product to which it is applied, and insufficiently preventing the damage to the environment by the waste for reducing the other additives used and the product produced using the waste.
Consequently, all the above-mentioned problems have made it necessary to make an innovation in the relevant technical field.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a concrete comprising dusts and/or ashes obtained from low-cost, high value-added ferrochrome chimneys as a component, in order to eliminate the above-mentioned disadvantages and bring new advantages to the relevant technical field.
An object of the invention is to reduce the waste of production containing heavy metals and to use high value-added raw materials with increased environmental awareness.
An object of the invention is to provide a cement substitute and a binding raw material with higher strength than cement.
An object of the invention is to produce a concrete with added value with increased environmental awareness.
DETAILED DESCRIPTION OF THE INVENTION
In this detailed description, the subject of the invention relates to a method of producing a product of concrete which comprises dusts and/or ashes obtained from low-cost, high-value-added ferrochrome chimneys as a component and is described only with examples for a better understanding of the subject without any limiting sense.
In the invention, "ferrochrome" refers to an alloy consisting of chromium and iron, comprising small amounts of elements such as carbon and silicon. In the art, ferrochrome is divided into three groups as "high, medium and low carbon ferrochrome" according to the amount of carbon contained therein.
In the invention, “high carbon ferrochrome” is the most common alloy comprising 60% to 70% chromium by weight or mass and 4% to 6% carbon by weight or mass.
In the invention, "ferrochrome chimney dust" refers to a waste material obtained in large amounts from the gas cleaning facility of the ferrochrome industry. Said waste material is released into nature without preventing pollution, being controlled, or taking remedial measures, thus occupying acres of valuable land.
In the invention, a "submerged electric arc furnace" is essentially defined as a furnace used for the production of ferro alloys, where the furnace electrodes are buried deep within the furnace load, and a reduction reaction takes place near the tip of the electrodes to facilitate the furnace process.
In the invention, a “backfill concrete” is a self-compacting cementitious slurry consisting of a filler instead of a compacted ground filler, or a fine aggregate used as a filler, or a mixture of a filler, water and a cementitious material.
In the invention, a "cement" is essentially meant as a hydraulic binding material obtained by grinding a mixture of natural limestones and clay after heating at high temperatures.
The present inventors suggest to reduce the use of cement in the relevant technical field and instead to use ferrochrome chimney dust, which is a recycling product providing high strength and heat resistance, and to use the same in obtaining backfill concrete as a raw material. Accordingly, the invention prevents environmental pollution and material waste as a result of a reduction in the amount of waste by adding added value to the waste material and a reduction in use of cement by the use of alternative materials. In the invention, another advantage of reducing cement production with ferrochrome chimney dust in the production of backfill concrete used in the mines is that the desired value in the uniaxial compressive strength results was 12 MPa in the experiments conducted without using chimney dust, while an increase in the uniaxial compressive strength of the backfill concrete used in the mines is detected when the chimney dust released from the submerged electric arc furnaces is used, resulting in an increase in the strength value of the backfill concrete.
As it is known in the art, clinkers, which are the cement intermediate products, are formed during the cement production. Portland cement is formed by grinding clinkers with certain amounts of gypsum. In this way, the compounds 3CaO.SiO2, 2CaO.SiO2, 3CaO.AI2O3 and 4CaO.AI2O3.Fe2O3 are included as the main phases in the cement and clinkers.
In the invention, the dusts and/or ashes obtained from the ferrochrome chimneys are preferably high carbon ferrochrome chimney dusts and ashes resulting from the submerged arc furnaces.
In a preferred embodiment, the ferrochrome chimney dusts in the concrete of the invention should be between 200 pm to 400 pm. The limestones and clays used during the cement production are expected to be within the specified ranges of grain size. This is because the coarse grained components may cause problems in obtaining concrete. Additionally, it may cause problems in the formation of the desired phases and bond structures. Therefore, the ferrochrome dusts to be used for the cement obtained are important to have the specified grain sizes. In the invention, said ferrochrome chimney dusts are expected to preferably have a grain size of 300 pm. Accordingly, in this invention, no sizing process or any pre-treatment is performed on the chimney dust released from the submerged electric arc furnaces during the production of each high carbon ferrochrome, and it is used directly. In this aspect, the invention provides an advantage in terms of production time and cost.
In a preferred embodiment, ferrochrome chimney dusts are included in the concrete as a raw material in the range of 0.01% to 20% by weight. It is observed that the mechanical strength values of the cement obtained at values above the specified value ranges decrease. It has been determined that the targeted cement form and mechanical strength values are not met at values below the specified value ranges.
In the invention, dusts and/or ashes obtained from the ferrochrome chimneys are mixed with other components in the specified weight ratios and subjected to the processes to obtain concrete. Said resulting concrete premix is preferred to be obtained at ambient temperatures between 1 to 55 °C. Additionally, the setting time is expected to be between 3 to 24 hours. The resulting concrete is then placed into the molds for use and allowed to shape.
A premix is prepared for the concrete of the invention using the other components and methods previously known in the art. This premix preferably contains dusts and/or ashes obtained from the ferrochrome chimneys in the range of 0.01% to 20%. Mixing is carried out for a period of 1 to 60 minutes, depending on the amount of the components. The resulting mixture is poured into the clay molds. Here, the process
temperature is between 1 to 55 °C. Again, the setting time is between 3 to 24 hours depending on the characterization of the components. The concretes set are removed from their molds and placed in curing pools.
It has been analyzed that the concrete comprising dusts and/or ashes obtained from the ferrochrome chimneys as a component in the weight ratios specified in the invention complies with TS 500, TS EN 206-1 and TS EN 450-1 standards by the tests performed. In addition, the Cr (VI) amount of the concrete obtained was determined to be in compliance with the Regulations on Water Pollution.
The concrete comprising dusts and/or ashes obtained from the ferrochrome chimneys as a component in the weight ratios specified in the invention has been determined to comply with TS 2513 (average hardness is appropriate), TS EN 1097-6 (water absorption and grain density is found to be appropriate), TS 9582 EN 933-3 (flatness index is found to be appropriate), TS 3530 EN 933-1 (fineness values are found to be appropriate), TS EN 1367-01 (mass loss after freezing and thawing is found to be appropriate), TS EN 1744 (acid-soluble sulfate ratio is found to be appropriate) standards.
The concrete of the invention comprising dusts and/or ashes obtained from the ferrochrome chimneys as a component in the specified weight ratios has been determined to have a compressive strength between 23.79 to 37.83 MPa in the tests in accordance with TS EN 206-1 standards.
In addition, Cr (VI) analyzes were observed to be in the range of 0.008-0.027 mg/L, which is much lower than the desired values (0.5 mg/L) according to the Regulations on Water Pollution.
Accordingly, the invention reduces the amount of cement in the total mortar by using chimney dust along with cement in the backfill concrete mortar used in the mines, provides added value and high strength to the backfill concrete currently obtained and reduces the concrete production cost.
The scope of protection of the invention is specified in the attached claims and cannot be limited to what is explained in this detailed description for the exemplary purposes.
That is because it is clear that a person skilled in the art may represent similar embodiments in the light of what has been explained above without departing from the main spirit of the invention.
Claims
CLAIMS A product of concrete comprising ferrochrome chimney ashes and/or dusts as a raw material in accordance with the values of ASTM TS 500, TS EN 206-1 ve TS EN 450-1 , TS 2513, TS EN 1097-6, TS 9582 EN 933-3, TS 3530 EN 933-1 , TS EN 1367-01 , TS EN 1744 standards. A product of concrete according to claim 1 , characterized in that it comprises ferrochrome chimney ashes and/or dusts as a raw material in a range of 0.01% to 20% by weight. A product of concrete according to claim 1 or 2, characterized in that it comprises ferrochrome chimney ashes and/or dusts as a raw material in a range of 200 pm to 400 pm. A method of producing a concrete, characterized in that the following process steps are followed:
Preparing a premix comprising ferrochrome chimney ashes and/or dusts as a raw material in a range of 1% to 20% by weight, adding water to the mixture, and performing mixing processes to obtain a homogenous mixture,
- Casting the premix into the molds and waiting for setting, Removing the concretes from molds after the setting process. A method according to claim 4, characterized in that the ferrochrome chimney ashes and/or dusts are in a range of 200 pm to 400 pm in the premix. A method according to claim 4 or 5, characterized in that the premix is kept at a temperature between 1 to 50 °C after casting into the molds. A method according to one of claims 4-6, characterized in that the setting time is between 3 to 24 hours.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TR2022/018844 | 2022-12-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2024123281A1 true WO2024123281A1 (en) | 2024-06-13 |
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