WO2013136345A2 - A biodegradable and eco - friendly formulation useful as a dust suppressant and a process for the preparation thereof - Google Patents

Description

A BIODEGRADABLE AND ECO - FRIENDLY FORMULATION USEFUL AS A DUST SUPPRESSANT AND A PROCESS FOR THE PREPARATION THEREOF

Field of Invention

The present invention relates to a biodegradable and eco-friendly formulation useful as a dust suppressant and a process for the preparation thereof. In particular, the present invention provides a formulation to control the dust / to provide a dust free environment for unpaved haul roads, stock piles, material handling after blasting in mines and other dust prone areas. It is noteworthy to state that with the advent of large scale mechanized in open cast mining operation, the mines are facing a very serious hazard in the form of dust which, besides reducing visibility in certain areas, is also creating serious health hazards for worker population, vegetation, forests, equipment/ machine, cattle, animals and water resources.

Background of Invention & Description of Prior Art

Mining is a dust prone occupation and almost every major process in mining contributes to the atmospheric load of suspended particulate matter. Prolonged exposure of this dust is known to cause various respiratory diseases including deadly pneumoconiosis among the miners.

Open cast being highly productive method in mining industries accounts for major share of coal/mineral production which is proportionately related to the dust generation in atmosphere mainly through movement of dumper and tipper. This haul road dust is major source of fugitive dust generation in open cast mines. The coarser dust of suspended particulate matter generated by unpaved haul roads settles in due course while the finer dust remains suspended in the atmosphere for a very long period.

The dust generation is directly related to the stabilization of soil texture of roadbed and physico chemical properties of dust suppression chemicals with respect to temperature. The finer particles of unpaved haul road bind coarser particles which helps the stabilization of road bed. For better compaction of the haul road, the finer particles of 100 mesh size should be at least 10% (S Mishra, 2001). An unpaved haul road is normally made up of two beds; (a) top surface layer which depends upon the soil texture and operational environment and (b) lower layer made up of native soil. The application of dust suppression chemical on the surface layer may create a third layer, which is made up of soil and dust suppression chemical that acts as a pavement layer. Unpaved haul roads in coal mines are a veritable source of dust pollution supporting normally 10 to 15mm of dust on its surface (Pandey, et ah, 1999). Dust from haul roads gets lifted and floats in the air during movement of trucks and forms a dust cloud. With an increase in the weight of trucks, speed and frequency of traffic, the cloud may appear to be continuous causing delays and difficulties. During continuous dumper runs, dust loads of surrounding atmosphere builds up both vertically and horizontally.

Application of water at frequent intervals remained by far the most practical solution for the control of dust on haul roads. Water applied in the conventional way gets dried up fast, and its replenishment at frequent intervals (up to 15 times a shift) becomes necessary for effective dust control which adds significant cost. In a case of Block II, Opencast Project of Bharat Coking Coal Limited (BCCL), water spraying over a 3 km long, 20 m wide haul road cost Rs 25 000 over a period of one year (Pandey, et ah, 1999). It becomes more cumbersome and costly where water is not easily available. Unfortunately, water becomes a scare resource in summer when it is required most. Besides, water has a poor wetting ability for coal. Therefore instead of penetrating into the dust and consolidating it, it flows down the sloppy road and make it muddy.

A number of techniques have been adopted addressing these issues which includes application of hygroscopic chemicals like calcium/magnesium to increase water retentivity. These chemicals require repeated application as they are re-dissolved in subsequent water sprays and tend to drain out to lower levels in the usually sloppy mines, adding to cost of treatment. Spray with oil-water emulsion also helps to consolidate dust but it does not penetrate deep and underlying dry dust layers gets airborne quickly during dumper movement. Some surface crusting agents like cohrex have also been tried which may need weekly or daily application. CSIR-CIMFR, Dhanbad has contributed many environment friendly and techno-economically viable methodologies for controlling dust in unpaved mine haul roads. The techniques of dust control are gaining industry interest in recent years mainly for two reasons: (a) dust generation has increased significantly due to higher mechanisation and the introduction of mass production technologies to meet our growing production needs making application of dust control mechanism inevitable, (b) growing consciousness of environment and stricter environmental compliance mechanisms has put constant pressure on the mining industry for regular use of dust control practices.

Prolonged exposure of respirable dust leads to serious health hazards to the workers including a number of deadly diseases like silicosis, pneumoconiosis, bronchial asthma, fibrosis of lungs, tuberculosis (T.B.) etc. Broken coal / stone dust particles are of two types: rounded & angular. Angular particles of dust are very harmful for the health. As 5 micron size dust is not controlled by the nostrils, fine angular dust of 5 micron penetrates easily into lungs and causes lung diseases in due course. Dust concentration observed at haul roads is often more than 10 mg/m³ which restricts dumper movement/speed due to poor visibility and adversely affects the transportation of mineral/coal and hence hampers the production. Corrosive nature of the dust shortens the life of costly heavy earth moving machinery (H.E.M.M.) & increases their maintenance cost. These dust particles also shorten the life of lubricants affecting operating efficiency of the H.E.M.M. This is also a potential safety hazard in opencast mines. In the winter period, dust is not settled easily and remains air bome for a longer period, while in the summer period, although the dust settles easily but the dust generation is too high. Therefore, the artificial aid to dust consolidation is required in both summer as well as winter seasons to effectively control/prevent the national loss. Dust control involves either dust consolidation or dust capture. Dust consolidation is normally practiced for settled dust which becomes air borne in favorable condition e.g. haul roads of open cast mines. Dust collection or capture is resorted to when it is airborne. In these cases dust is collected close to its source of generation for effective result and therefore the method is useful for controlling dust generated in localized spaces or point sources like drilling, blasting, crusher house and conveyor transfer points with the help of special types of dust capture arrangement. Dilution of dust is limited to small concentration of dust only.

Water spraying is the still the most prevalent method to control the mine dust. But following problems are experienced on spraying water to control the dust in/around the mining industries:

• Water - spray attracts only heavier particles leaving fine particles to continue to blow away.

• Water evaporates quickly & therefore consolidated surface dry up very fast in hot and dry climates. Thus, it possesses very little ability to suppress dust.

• The finer particles formed as DUST FILM particles dry very fast and blow away with water.

• The air borne dust is not absorbed / attached with plain / simple / normal water. When huge amount of water is sprayed to control dust completely, mud formation is a regular phenomenon. Thus, higher amount of water spraying per square meter of area of haul road is required to control the dust effectively. Moreover, floating dust is not controlled/ suppressed. •

Some dust suppressing chemicals have also been tried in open cast mining operations but the following problems were experienced with the use of these chemicals:

° No grading Operation is allowed.

° No Dozer movement is allowed.

° Bigger Size of potholes is produced in haul roads.

° The chemicals produced film & carpeting layer on haul roads which are scratched out easily on the movement of Grader, Dozer and H.E.M.M.

Reference is made to S. K. Mishra, TETRA Technologies, Inc.; The Woodlands, TX, D. Saylak, R. L. Lytton, D. Sinn, Texas A & M Univ., College Station, TX; SME Annual Meeting; Feb. 23- 25, 2001, Denver, Colorado) in which the CaCh was used as a dust suppression chemical for stabilization of roadbed. In the referred publication road bed stabilization was highlighted by treatment of unpaved road bed in primary stage. The per annum application of CaCl2 at a rate of 38% concentration was 0.25 gallon per yard of road surface and at the secondary stage of application it was twice weekly. Reference may be made to U.S. Pat. No. 4, 087, 572 which discloses a combination of organic polymer latex such as a styrene - butadiene inter polymer and a silicone applied to the surface of coal pile or other mass of finely divided particulate materials. In addition, a wetting agent may be incorporated to prevent premature coagulation. The combination is applied as an aqueous mixture such as by spraying. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine.

Reference may be made to U. S. Pat. No. 4, 551, 261 which discloses the suppression of dust with aqueous foam comprising a foaming agent and an elastomeric water insoluble polymer. The foam provides immediate dust suppression and eases application. The polymer coats the material and continues to suppress dust generation during handling of the material after the foam has collapsed. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine.

Reference may be made to U.S. Pat. No. 4,594,268, which discloses the use of at least one methacrylate polymer for dust suppression. The methacrylate polymer provides dust suppression when applied to a wide variety of materials. After application, the polymer provides a tacky, water resistant coating which effectively prevents dusting while additionally acting as an anti freezing agent. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine.

Reference is made to U. S. Pat. No. 4, 801, 635 wherein recited is a combination of water-soluble anionic acrylic polymers, non ionic glycol polymers and anionic as well as non ionic surfactants useful for the control of dust emission into the environment. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine. Reference may be made to U.S Patent No. 4,780,233 which discloses a method and composition for controlling fugitive dust particles, which comprises oil containing dust control treatment including a small amount of water insoluble elastomeric polymer. The inclusion of a small amount of elastomer significantly improves the dust control performance. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer* grader and dumper movement operation in the mine.

Reference is further made to U. S. Pat. No. 3, 954, 662 by Salyer et al., which discloses aqueous formable compositions and their use to suppress coal dust. The compositions contain water, an inter-polymer of a polymerizable vinyl ester and a partial ester compound inter polymerizable with vinyl ester, and a detergent wetting agent. Inter-polymers which are soluble in water at room temperature in the amount required in the composition such as vinyl acetate / maleic anhydride copolymer esters are preferred. The inter-polymer binds the coal dust and keeps the dust particles encapsulated after the foam has collapsed. The inter-polymers also gives body to the foam and thus promotes the desired degree of stability of the foam which in most cases should be of limited duration so as not to interfere with mining operations. The detergent wetting agent promotes foaming and wetting of the coal by water. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine.

Reference is made to U. S. Pat. No. 4, 087, 572 by Nimerick, which recites that a combination of organic polymer latex such as a styrene - butadiene inter-polymer and a silicone is applied to the surface of a coal pile or other mass of finely divided particulate material. An additional wetting agent, in addition to the one used in making the latex, may be incorporated to prevent premature coagulation of the latex and enhance wetting and penetration by the latex. The combination may be applied as an aqueous mixture such as by spraying. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine. Reference may be made to U. S. Pat. No. 4, 417, 992 by Bhattacharyya et al. which describes coal and other mineral dust control methods in which the mineral is sprayed with a liquid dispersion of a highly branched water swellable polymer of acrylamide or an acrylamide - acylic acid copolymer branched and / or cross - linked with a multifunctional unsaturated monomer containing more than one ethylenically unsaturated group. The dispersions of the examples contain nonylphenol ethoxylate. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine.. Reference may be made to U.S. Pat No. 2, 854, 347 by Booth et al., wherein elastomeric substances such as styrene - butadiene copolymers are applied to the surface of coal and other minerals. The elastomeric film immobilizes dust and prevents water and wind erosion. The elastomers may be sprayed on the surface in latex form. The surfaces are preferably pre - wet with water or solutions of suitable wetting agents in water to lessen the quantity of elastomer needed. However, the drawbacks include poor penetration in soil, film formation over the soil which is removed during dozer, grader and dumper movement operation in the mine..

Reference is made to U.S. Pat. No. 4, 136, 050 and 4, 171, 276 by Brehm which describes a dust suppression method in which the dust particles are treated with an aqueous solution of alkylphenoxy polyethoxy ethanol and a copolymer of ethylene oxide and propylene oxide. Spraying the solution on their surfaces preferably treats the particles. However, the drawbacks include its non-biodegradable nature, phenolic composition which is banned in most of the developed and developing countries. Fine dust is rendered air borne and remains in the atmosphere for a considerable length of time thereby polluting the environment significantly. The best method of preventing roadway dust getting converted into air borne contaminates is to consolidate it by wetting the dust with water spray. But water sprays alone do not produce good wetting of all deposited dust and a large quantity of water may be needed frequently for producing effective result due to propensity of water to evaporate in hot and dry conditions. Further, the fine dust is deposited over water droplets and forms dust film. Wetting agent, if added, would increase the ability of water to consolidate and hold together the smaller dust particles.

Literature review suggests that a number of chloride, resin, phenol and oil based compounds have been used as dust suppressing products but these are now banned worldwide including India due to their adverse environmental consequences. A number of legislative provisions for the same have been enacted e.g., RCRA (Resource Conservation Recovery Act, USA) guidelines of USEPA and DGMS circulars in India. Many of the dust suppression chemicals have a polymer base which also does not fulfill RCRA & Indigenous guidelines with respect to physico - chemical properties including reduction in surface tension to water below 35 dynes / centimeter, which is an important parameter for improvement of water for soil penetrations properties for the unpaved haul capacity of the soil. Re wetting properties of soil is highly affective due to which the consumption of water after first phase of water spraying is reduced and evaporation of water is low which reduces the consumption of water by 25 to 40 % depending upon the temperature, pressure, wind velocity, humidity, speed of dumper, load of dumper, traffic density, etc.

A summary of hitherto reported products useful as dust suppressants is provided herein below along with their drawbacks:

Earlier Product type Drawbacks

Chloride Based Disturbs the ozone layer on liberation of chlorine after

longer time & increase TDS of spillage water

Oil Based Causes slipping of the vehicle on the haul roads if

petroleum oil is used. Less biodegradable & floats on the surface of water. If burnt, impurities produced are non biodegradable & carbonaceous.

Phenol Based Carcinogenic & non biodegradable

Polymer based Form a film which is removed by HEMM momentum & in

certain cases application is after digging the road, so it disturbs the mines' routine work

Cationic Base Normally soluble in acidic pH which is not advisable

Surfactant Base Certain surfactants do not penetrate the soil or are non- biodegradable. Product based on alkyl phenol ethoxylated

are surfactants which is non biodegradable

Therefore, in order to overcome the aforesaid difficulties as reported in the hitherto known prior art, the inventors of the present invention realized that there exists a dire need to provide a formulation which is useful for suppressing the dust in a variety of areas including but not limited to unpaved haul road and materials handling after blasting, stock piles in mines and other dust prone areas like dam, building construction sites, parking areas, race track, play ground, ungrass open fields etc.

Objects of the invention

The main object of the present invention is thus to provide a novel formulation which is useful as a dust suppressant and which obviates the drawbacks of the hitherto known prior art.

Another object of the present invention is to provide a formulation for suppression of dust in mines and dust prone areas, which is cost effective in controlling the fugitive dust generation with lesser interference with mining activities.

Yet another of the present invention is to provide a formulation which is eco-friendly, bio degradable and non-toxic and is useful as a dust suppressant. Summary of the Invention

The present invention relates to a unique dust suppressant formulation which is eco-friendly, bio degradable, does not have any toxic or adverse effect on human as well as plant growth and gives required/ desire level of dust reduction on unpaved haul roads/ material handling/ stock piles for mines.

The developed product can control dust on all types of haul roads for both coal and non-coal mines, stock piles, blasted material handling and other dust probe areas like dam, building construction sites, play grounds and ungrass fields. The different components of the formulation are blended together to obtain a product which can provide optimum dust control with maximum savings. The product is non toxic, biodegradable, meets all the safety standards as per statutory requirement and has been proved to be very effective in controlling dust at haul road (Trivedi and Kumar, 2011).

The prepared formulation is poured into the conventional water spraying container in recommended dilution and sprayed on the haul road surface in a conventional way. It improves water penetration, water retention, agglomeration of dust and reduces the water consumption of dust with improved dust control.

In an embodiment of the present invention, the formulation comprises of Alkali alcohol ethoxylate, Alkali sulphated easter with di basic acid & Alkyl ester of di basic acid sulphonate.

In another embodiment, the present invention provides a composition suitable for dust suppression which is not a mere admixture but a synergistic mixture having physico-mechanical and physico-chemical properties different from that of constituents and which are distinct and different from the aggregation of the properties of the individual ingredients.

In yet another embodiment, the present invention provides a composition useful for suppressing the dust in a variety of areas including but not limited to unpaved haul road and materials handling after blasting, stock piles in mines and other dust prone areas like dam, building construction sites, parking areas, race track, play ground, ungrass open fields.

In still another embodiment, the present invention provides a process for the preparation of the dust suppressant composition comprising blending the components I, I and III at rpm of 1400 to 2800 at 40 to 80 ⁰ C temperature for 4 to 6 hours.

Detailed Description of the Invention

Chemical dust suppressants are now-a-days gaining more acceptances in the industry for controlling dust at haul roads probably due to the fact that the application methodology for these chemical dust suppressants fits well to the conventional water spraying. The present invention recites a novel dust suppressant formulation which has been developed using commercially available chemicals. The basic ingredients of the composition include (a) fatty acids (b) fatty alcohol and (c) their derivatives like carboxiamide, amine, ether and ester; derived from commercially available fatty acids. The formulation was prepared by blending of the following three components in desired proportions to achieve the standard formulation: 1. Component I - is non-ionic and is selected from the group consisting of :

RCO.O(Ri)„H, RO(Ri)„H, RCONH.O(R₂)_nH or R NH O (X₃)„H

wherein, Ri and R2 represent ethylene or propylene; X₃ is the moiety remaining after reaction of R3 with R-NH₂; R3 IS gly colic acid; and R is Ci2to C₂o carbon chain which is either alcohol, fatty acid, carboxy amide or amine and n ranges between 1 to 20.

The reactions to be prepare the constituents of component I were carried out at 45 to 85 degree C ' for 4 to 8 hours in hydroxide of sodium, potassium, zinc or lithium catalyst.

2. Component II - is an anionic product in the form of sodium, potassium, zinc or lithium salt of sulphated ester/alcohol (C6 to C18 linear chain alcohol) which is the condensation reaction product prepared from cis or trans forms of dibasic acid or aliphatic or aromatic anhydride with C6 to Cis aliphatic alcohols in presence of acid catalyst to remove water molecule. The reaction takes places between 140 to 210 degree C for 4 to 12 hours. The resultant product is sulphated at 60 to 130 degree C for 4 to 12 hours & neutralized with hydroxides of sodium, potassium, zinc or lithium to adjust the pH to 7 to 8 to obtain component II:

XiCO.O X₂ - SOsNa/K/Zn/Li

wherein, Xiand X represent the moieties remaining after the reaction of Ri with R₂ and wherein Ri is a dibasic acid selected from pthalic, succinic, maleic, or tartaric acid in either cis or trans form or any other form which can react with R₂ as a C₆to Ci₈ aliphatic alcohol. 3. Component III is ethylene glycol having molecular weight between 62 to 1500 which was sulphated in presence of catalyst like urea and neutralized with hydroxide of sodium, potassium, zinc or lithium and is represented by:

(HO - Ri - 0)„ SO3 Na/K/Zn/Li

wherein, Ri is ethylene and n ranges between 1 to 45.

Reactions to prepare the components of the claimed formulation:

The reactions to prepare component I were carried out at 45 to 85 degree C for 4 to 8 hours in hydroxides of sodium, potassium, zinc or lithium catalyst and are represented by:

R-COOH + (Ri-0)a = RCO.O(Ri)nH

R-OH + (Ri-O)n = R O (Ri)nH

R-CONH2 + (Ra-0)„ = R C0NH.0 (R₂)_nH

R-NH₂ + (R₃)„ = R NH O (X₃)„H wherein, Ri and R2 represent ethylene or propylene; R₃is glycolic acid; X₃ is the moiety remaining after reaction of R₃ with R-NH₂ and R is Ci₂to C₂o carbon chain which is either alcohol, fatty acid, carboxy amide or amine and n ranges between 1 to 20.

The reaction to prepare component II takes places between 140 to 210 degree C for 4 to 12 hours. The resultant product is sulphated at 60 to 130 degree C for 4 to 12 hours using sulfuric acid & neutralized with hydroxides of sodium, potassium, zinc or lithium to adjust the pH in the range of 7 to 8.

Ri + R2 _β X1CO.OX2 _β XiCO.O X₂ - SOsNa/K/Zn/Li

wherein, Xi and X₂ represent the moieties remaining after the reaction of R_x with R₂ and wherein Ri is a dibasic acid selected from pthalic, succinic, maleic, or tartaric acid in either cis or trans form or any other form which can react with R₂ as a C₆to Ci₈ aliphatic alcohol. Component III is ethylene glycol having molecular weight between 62 to 1500, which was sulphated in the presence of catalyst like urea and neutralized with hydroxides of sodium, potassium, zinc or lithium and is represented by:

(HO - Ri - O)„ SO₃ Na/K/Zn/Li

wherein, Rl is ethylene and n ranges between 1 to 45.

Different dust suppressant formulations were prepared by mixing the above three basic components in a definite ratio which was arrived after extensive experimentation to obtain the desired dust suppressant formulation having desired properties and results as claimed in the present application. The above said formulations were prepared by blending the ingredients at rpm of 1400 to 2800 at 40 to 80 degree C temperature for 4 to 6 hours.

The desired formulation was chosen to be formulation no. 4 which depicted the following physico - chemical properties as established in laboratory and field trials:

Test Properties Result

Physical Form Pale Yellowish Colour Liquid

Ionic Character Anionic / Non-ionic

Molecular Weight 439 approx (average)

Major Component Ratio Carbon : 58.22 Parts

Oxygen : 27.95 Parts

Hydrogen :09.37 Parts

Sulphur : 02.17 Parts As a sulphated product

Sodium : 01.56 Parts As a sodium salt

Nitrogen : 0.73 Parts

Active Matter/ Solid Content 88+ 2%

Effect on Aquatic Life No adverse effect on Pond Fish

Toxicity Non-Toxic, Easily Bio - degradable & Environment Friendly.

Flash Point More than 180 Deg Centigrade

Flammability Non flammable at normal temperature

Test Properties Result

Flow Characteristic Free Flowing Liquid abovelO Deg Centigrade

Conductivity Mixing with water shows Ionising

Surface Tension 28+ 3 Dynes / Centimetre on 1:2500 & 1:5000 Dilution

Wetting Properties Minimum 70% in 1:2500

Minimum 60% in 1:5000

Penetration in Soils Minimum 10mm within 5 days consecutive treatment

Agglomeration Soils are agglomerated from the first day but result is observed from the fourth day with necked eyes after consecutive treatment method.

4mm - by single treatment

The said formulation may be used in the unpaved haul roads, stock pile, blasted material handling in mines and other dust prone areas for dust free workplace with significant cost savings. The methodologies of application of the developed formulation is as follows:

(a) The haul roads are first of all graded with the help of grading equipment.

(b) The developed formulation is mixed with water in the ratio of 1:1000 to 1:10000 (W:V) by weight by volume i.e. 1 Kilogram developed formulation is mixed with 1000 to 10000 litres of water.

(c) Application of the diluted formulation can be done from an ordinary tank, lorry or converted tanker from dumpers normally available in a colliery in India.

(d) Initially ¾ of the tanker is required to be filled by water and then required amount of chemical is poured into it. Remaining part of the tanker is then filled up with water. No stirring is required; the chemical is automatically mixed with water.

(e) The diluted product is sprayed uniformly on unpaved haul road at the rate of 2.5-4m² area per liter and blasted materials/stock piles at the rate of 4-10 1/m³ of blasted/stockpile materials. (f) The product is applied 3 times a day for first three days, two times a day for next three days (i.e 4^th to 6^th day) and subsequently single applications a day for achieving desired /claimed results. The intermittent normal water spraying (without chemical) is also required to ensure that a total of about 40-60% water is sprayed as compared to pre treatment water spraying level to achieve the desired level of reduction in dust level.

(g) For dust control in blasted material/stock pile handling, the diluted product is to be sprayed twice a day.

EXAMPLES

The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention.

Example 1

The basic ingredients of the composition include (a) fatty acids (b) fatty alcohol and (c) their derivatives like carboxiamide, amine, ether and ester; derived from commercially available fatty acids. The formulation was prepared by blending of the following three components in desired proportions to achieve the standard formulation:

Component I - is non- ionic and is selected from the group consisting of :

RCO.O(Ri)„H, RO(Ri)_nH, RCONH.O(R₂)_nH or RNHO(X₃)_nH wherein, Ri and R2 represent ethylene or propylene; X3 is the moiety remaining after reaction of R₃ with R-NH₂; R3 IS glycolic acid; and R is C₁₂ to C₂₀ carbon chain which is either alcohol, fatty acid, carboxy amide or amine and n ranges between 1 to 20. The reactions to be prepare the constituents of component I were carried out at 45 to 85 degree C for 4 to 8 hours in hydroxide of sodium, potassium, zinc or lithium catalyst.

Component II - is an anionic product in the form of sodium, potassium, zinc or lithium salt of sulphated ester/alcohol (C6 to Cie linear chain alcohol) which is the condensation reaction product prepared from cis or trans forms of dibasic acid or aliphatic or aromatic anhydride with Ce to Ga aliphatic alcohols in presence of acid catalyst to remove water molecule. The reaction takes places between 140 to 210 degree C for 4 to 12 hours. The resultant product is sulphated at 60 to 130 degree C for 4 to 12 hours & neutralized with hydroxides of sodium, potassium, zinc or lithium to adjust the pH to 7 to 8 to obtain component II:

XiCO.O X₂ - SOsNa/K/Zn/Li

wherein, Xi and X2 represent the moieties remaining after the reaction of Ri with R₂ and wherein Ri is a dibasic acid selected from pthalic, succinic, maleic, or tartaric acid in either cis or trans form or any other form which can react with R2 as a C6 to G₈ aliphatic alcohol.

4. Component III is ethylene glycol having molecular weight between 62 to 1500 which was sulphated in presence of catalyst like urea and neutralized with hydroxide of sodium, potassium, zinc or lithium and is represented by:

(HO - Ri - 0)„ S0₃ Na/K/Zn/Li

wherein, RI is ethylene and n ranges between 1 to 45.

Reactions to prepare the components of the claimed formulation:

The reactions to prepare component I were carried out at 45 to 85 degree C for 4 to 8 hours in hydroxides of sodium, potassium, zinc or lithium catalyst and are represented by:

R-OH + (Ri-O)n = R O (Ri)nH

R-CONH2 + (R₂-0)„ = R CONH.O (R₂)_nH

R-NH₂ + (R₃)n = R NH O (X₃)„H wherein, Ri and R₂ represent ethylene or propylene; R₃is glycolic acid; X3 is the moiety remaining after reaction of R₃ with R-NH₂ and R is G₂to C20 carbon chain which is either alcohol, fatty acid, carboxy amide or amine and n ranges between 1 to 20. The reaction to prepare component II takes places between 140 to 210 degree C for 4 to 12 hours. The resultant product is sulphated at 60 to 130 degree C for 4 to 12 hours using sulfuric acid & neutralized with hydroxides of sodium, potassium, zinc or lithium to adjust the pH in the range of 7 to 8.

5 Ri + R₂ p, X1CO.OX2 _β XiCO.O X₂ - SChNa/K/Zn/Li

wherein, Xi and X₂ represent the moieties remaining after the reaction of Ri with R₂ and wherein Ri is a dibasic acid selected from pthalic, succinic, maleic, or tartaric acid in either cis or trans form or any other form which can react with R₂ as a C6 to C_i8 aliphatic alcohol.

10 Component III is ethylene glycol having molecular weight between 62 to 1500, which was sulphated in the presence of catalyst like urea and neutralized with hydroxides of sodium, potassium, zinc or lithium and is represented by:

(HO - Ri - 0)n S0₃ Na/K/Zn/Li

wherein, RI is ethylene and n ranges between 1 to 45.

15

Example 2

Different dust suppressant formulations were prepared by mixing the above three basic components in a definite ratio which was arrived after extensive experimentation to obtain the desired dust suppressant formulation having desired properties and results as claimed in the 20 present application. The above said formulations were prepared by blending the ingredients at rpm of 1400 to 2800 at 40 to 80 degree C temperature for 4 to 6 hours.

Formulation no. 4 depicted the best result among all the nine formulations. EXAMPLE 3

Syntron Industries conducted a number of studies for dust control with the help of Dustron PC used in mines haul road. The results of these studies conducted at various coal and metal mines vis-a-vis conventional water treatment with respect to various parameter on these haul roads are being summarised in the following six tables.

Table 1: Water Tanker Coverage

Time taken for water 32 Minutes 40 Vlinutes 45 Minutes spraying in single trip (With

Chemical)

Table 2: STUDY OF WATER REQUIREMENT (METAL MINES)

Table 3: Study of Actual water Conservation in Metal Mines Haul Roads

From 7AM to 7 PM 24.00 tanker / trips 4.00 tanker / trips

From 7 PM to 7 AM 5.00 tanker / trips 1.80 tanker / trips

Actual water 15 tanker / trips 5 tanker / trips

Sprayed

Conclusion Unit: tankers/trip

A tual water Normal Water Water spray % Saving w.r.t % Saving required (A) Spray (B) with (^A) w.r.t (B) chemical (C'

29 15 5 82.76 66.67

Table 4: Study Results of Ambient Air Quality Monitoring by RDS

(SPM NRPM NRPM = 287 NRPM = NRPM = 272 NRPM = NRPM = 251 mg/m3) 488 1213

488 rotal = Total = 423 Total = Total = 413 Total - Total = 443

% of Dust 49.40% 43.89% 77.64%

Decrease

Table 5 : Moisture Study of Haul Road Soil (Coal Mines)

Table 6: MINES Haul Road ( Coal Mines Road ) Soil Sample Sieves Analysis Report

These studies reveal the significant improvement in water conservation on mine haul roads, including:

1. Water requirement decreases by more than 50% and a commensurate reduction in diesel consumption for running of water tanker. Moisture of haul roads increased three fold in comparison to normal watering.

2. Sieve test analysis of haul road dust with chemical and with water alone reveals that application of chemical improves agglomeration conditions as fines (size 0.5 mm or less) have been reduced after application of chemical by 80%. ADVANTAGES

On using the developed formulation in open cast coalmines and other dust prone areas, the advantages are as follows: The chemical compound is anionic / non-ionic, non- volatile, nonflammable & non-corrosive. So, it does not harm human health, equipment, etc. Better wetting 5 and reduced evaporation loss reduces water consumption by 25 to 40% depending upon the temperature, pressure, wind velocity, humidity, speed of dumper, load of dumper, traffic density, etc. It also helps to minimize road maintenance cost by improving the road surface. It reduces the diesel consumption of water tanker and other vehicle due to smooth & dust free roads. It also increases the life of tyres and the life of Lubricants by 20 to 25 %, the life of spare parts byl5 to

10 20 % due to increase in the life of lubricants and no wear & tear due to dust free environment & smooth haul roads. It also increases the life of water tanker and its spare parts due to its anti corrosive nature. It creates dust free environment thereby preventing dust inhalation by the workers. There is reduction in danger to the human health which may not be evaluated in terms of money. The occurrence of different diseases due to the harmful physical and chemical nature of

15 dust is brought almost under control. It brings indirect advantages such as: saving in medical expenses & reduction in work output due to suffering of mining personal from diseases. A clean environment results in better production rate. The haul roads will be clear for vision and movement of dumpers & other vehicles will be free and unrestricted thereby improving the production capacity. There is no chance of accident of vehicle due to clean environment. Less

20 servicing is required due to reduced dust deposition on various moving parts of vehicles. Less grading is required due to smooth and hard roads. No complaints of pollution from villagers residing nearby. The chemical is free from any negative side effect e.g. fertility of wild plant is not decreased. There are no adverse effects on earthworm, aquatic life and plants. Reduced loss in time for maintenance which is difficult to be evaluated in terms of money does significantly

25 increase the productivity.

Claims

We claim:

1. A biodegradable and eco-friendly formulation useful as a dust suppressant, wherein the said formulation comprising component I, component II and component III in a ratio of 30:0.5:6 to 75:35:35 wherein component I is non-ionic and is selected from the group consisting of:

RCO.O(R₁)_nH, RO(Ri)_nH, RCONH.O(R₂)„H or R H O (X₃)_nH wherein, Ri and R2 represent ethylene or propylene; X₃ represents the moiety remaining after reaction of R₃ with R-NH2, wherein R₃is glycolic acid; and R is Ci₂to C20 carbon chain which is either alcohol, fatty acid, carboxy amide or amine and n ranges between 1 to 20; component II is represented by

XiCO.O X₂ - SOaNa/K/Zn/Li

wherein, Xi and X₂ represent the moieties remaining after the reaction of Ri with R₂ and wherein Ri is a dibasic acid selected from pthalic, succinic, maleic, or tartaric acid in either cis or trans form or any other form which can react with R₂ as a C6 to Cie aliphatic alcohol;

component III is represented by

(HO - Ri - 0)_n S0₃ Na/K/Zn/Li

wherein, Ri is ethylene and n ranges between 1 to 45.

2. A composition as claimed in claim 1, wherein component I is prepared at 45 to 85 degree C for 4 to 8 hours in alkali hydroxide of sodium, potassium, zinc or lithium catalyst by employing the following reactions:

R-COOH + (Ri-C n = RCO.O(R „H

R-OH + (Ri-O)n = R O (Ri)„H

R-CONH2 + (R₂-0)„ = R CONH.O (R₂)_nH

R-NH₂ + (R₃)„ = R NH O (X₃)„H wherein, Ri and R₂ represent ethylene or propylene; R₃ is glycolic acid; X₃ is the moiety remaining after reaction of R₃ with R-NH₂ and R is Ci₂to C20 carbon chain which is either alcohol, fatty acid, carboxy amide or amine and n ranges between 1 to 20.

3. A composition as claimed in claim 1, wherein component II is prepared between 140 to 210 degree C temperature for 4 to 12 hours and the resultant product is sulphated at 60 to 130 degree C for 4 to 12 hours followed by neutralization with hydroxides of sodium/ potassium, zinc or lithium at pH of 7 to 8 using the following reaction scheme:.

R1 + R2 _a X1CO.OX2 _β XiCO.O X₂ - SChNa/K/Zn/Li

wherein, Xi and X2 represent the moieties remaining after the reaction of Ri with R₂ and wherein Ri is a dibasic acid selected from pthalic, succinic, maleic, or tartaric acid in either cis or trans form or any other form which can react with R₂ as a C₆ to Cis aliphatic alcohol.

4. A composition as claimed in claim 1, wherein component III is ethylene glycol having molecular weight between 62 to 1500, which was sulphated in the presence of catalyst like urea and neutralized with hydroxides of sodium, potassium, zinc or lithium and is represented by:

(HO - Ri - 0)„ S0₃ Na/K/Zn/Li

wherein, RI is ethylene and n ranges between 1 to 45.

5. A composition as claimed in claim 1, useful for suppressing the dust in a variety of areas including but not limited to unpaved haul road and materials handling after blasting, stock piles in mines and other dust prone areas like dam, building construction sites, parking areas, race track, play ground, ungrass open fields.

6. A process for the preparation of the formulation as claimed in claim 1 comprising blending the components I, I and III at rpm of 1400 to 2800 at 40 to 80 degree C temperature for 4 to 6 hours.