Title:
Reagents for Enhanced Iron ore-Gangue Separation in reverse flotation process
Field of Invention:
The present innovation relates to the development of novel reagents for enhanced iron ore-gangue separation from low grade iron ore. More particularly, the process related to development of novel reagents for reverse flotation of iron ores. Long chain aliphatic compounds consisting ether, amine, acid and amide groups have been synthesized and their applicability as flotation collectors has been investigated in the reverse flotation process.
Background of Invention:
Iron ores containing high Al2O3/SiO2 gangue are detrimental to blast furnace and sinter plant operations. Therefore, these have to be beneficiated before being fed to the blast furnace for optimum production of steel. Kaolinite is a common gangue mineral frequently found in iron ore deposits. In iron ore flotation, both direct and reverse flotation techniques have been employed. Chemical reagents are the most important part of the flotation process. Based on their function, the reagents are divided into collectors, frothers, regulators and depressants. In flotation practice, the collector consists of a functional group that is polar and a nonpolar hydrocarbon chain or a polymeric compound. The selectivity of the collector and mineral interaction is determined by the characteristic of the functional group and the nature of the hydrocarbon chain. The capacity of a mineral to adsorb selectively a particular reagent molecule depends on a wide range of chemical, thermodynamic and steric factors. Iron ore bearing minerals like hematite can be floated by a variety of collectors, such as amines, oleates, sulfonates and sulfates. Beneficiation of iron ore slimes containing significant amount of Fe along with SiO2 and Al2O3 can be concentrated either by reverse cationic flotation of aluminosilicates (Kaolin) or direct anionic flotation of Fe. The cationic reverse flotation of aluminosilicates seems to be an attractive route for the concentration of low grade ores. However, this is not practiced widely as it is a very difficult task to float alumina. This is because alumina selective reagents are not available as flotation collectors. The collectors available for reverse flotation are mostly silica selective and applicable for ores outside India which have basically silica/quartz as the main impurity. Therefore, it is an important task to design and synthesize cationic collectors for reverse flotation, which can improve the selectivity and floatability of gangue minerals with respect to iron ore.

In past, a number of attempts have been made to separate gangue low grade iron ore. John D. et al, US patent number 2790778 mentioned about diacids which could be used as rust prevention agents. Joseph P. Laurino , US patent number 2009/0139929 mentioned about diacids and dioic acids as chelating agents. Patra et al, Indian patent filing number-(1123/KOL/2015) mentioned about guanidine based reagents for alumina separation from iron ore by reverse flotation process.
Primary, secondary and tertiary amines with a carbon chain of varying length have found use in froth flotation of silica and other ores. In case of iron ore flotation, amines have been used for reverse flotation process. But these are effective only when the gangue mineral is basically siliceous in nature. Also, reagents selective towards silica removal or binding from iron ore. are more common in the art. In our present invention, the reagents are not only selective towards alumina but also produce low alumina concentrates with high yields.
SUMMARY OF THE DISCLOSURE
The Present disclosure describes a compound of Formula-I

R =Alkylchains (C6, C8, C12l
Figure: 1
The present disclosure furthermore describes about use of the compound of formula-I for flotation of gangue selected from a group comprising alumina and silica.
Objects of the invention:
The object of the current invention is to develop reagents for enhanced iron ore-gangue separation from low grade iron ore.
Another object of the invention is to develop reagent for iron ore-gangue separation from low grade iron ore which have high affinity for alumina.
Still another object of the invention is to propose a synthesis scheme for long chain aliphatic compounds consisting ether, amine, acid and amide groups.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
The figures together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present disclosure where:
Figure 1 - General synthetic scheme for diacetamide as per the current invention
Figure 2 - Scheme of preparation of the compound of formula-I termed as 2,2' (Tridecylazanediyl) diacetamide
Figure 3 - Scheme of preparation of the compound of formula-2 termed Dodecyl bis(2-amino-2-oxoethyl) glycinate
Figure 4 - Scheme of preparation of the compound of formula-3 termed 2,2'-((l-(Dodecy lamino)-l -oxopropan-2-yl)azanediyl)diacetamide
Figure 5 - Scheme of preparation of the compound of formula-4 termed 2,2'-((3-(Dodecy lamino)-3-oxopropyl)azanediyl)diacetamide

The present disclosure describes novel flotation reagent for removal of aluminosilicate minerals from iron ore such as removal of alumina and silica from ore, such as low-grade iron ore.
The present disclosure describes a compound of formula as shown below:

R =Alkylchains (C8, C8, C12),
Figure: 1
Wherein, 'R' is an alkyl group or alkyl attached to amide having carbon atoms ranging from C6 to C12. The different R groups as per the current invention are listed in table 1.

The synthesis scheme as per the current invention is depicted in figure 1. N, N- dialkylation reaction was performed by alkylamine (hexylamine, octylamine and dodecylamine) reacts with 2 moles of chloroacetamide in solvent such as (tetrahydrofuran, acetonitrile, dichloromethane and ethyl acetate) using a base (triethylamine, sodium hydroxide and pyridine) at 70 oC under nitrogen atmosphere for 6 hours to obtained white solid with 80% yield.

Synthesis of formula 1 compound - 2,2'-(Tridecylazanediyl)diacetamide:
Figure 2 depicts the reaction scheme for the synthesis of formula 1 compound as per the
current invention.
Experimental procedure for Synthesis of formula 1 compound
Charge dodecylamine (1 eq.) into a clean and dry B flask. Charge THF 3 vol. and stir for 10
min under nitrogen at room temperature to get uniform solution. Charge triethylamine (2.1 eq.)
into the reaction mass under nitrogen atmosphere and stir for 10 min. add chloroacetamide (2.1
eq.) portion wise at room temperature under nitrogen atmosphere. Raise the temperature 70 oC
and stir for 6 h. Monitor the reaction by TLC after the ensuring the completion of reaction add
water 5 vol. and stir for 15 min white precipitate formed. Filter the solid suck dry for 10 min
and dry under vacuum dry oven at 45 °C to 50 °C. Compound 1 obtained as a white solid with
80% yield.
Synthesis of formula 2 compound Dodecyl bls(2-amino-2-oxoethyl) glycinate :
Figure 3 depicts the reaction scheme for the synthesis of formula 2 compound as per the current invention.
Experimental procedure 2,2'-(dodecylazanediyl)diacetamide:
Charge glycine (1 eq.) into a clean and dry B flask. Charge THF 3 vol. and stir for 10 min under nitrogen at room temperature to get uniform solution. Charge triethylamine (2.1 eq.) into the reaction mass under nitrogen atmosphere and stir for 10 min. add chloroacetamide (2.1 eq.) portion wise at room temperature under nitrogen atmosphere. Raise the temperature 70 °C and stir for 6 h. Monitor the reaction by TLC after the ensuring the completion of reaction 2A allow the reaction mass to cool to room temperature add (CDI 1.1 eq.) and stir for 4 h at 70 °C under nitrogen atmosphere. Check TLC after completion of the reaction to confirm 2B and allow the reaction mass to cool to room temperature. Add dodecylamine (1 eq.) and stir for 6 h at 70 °C under nitrogen atmosphere. Progress of the reaction was monitored by TLC, add water 5 vol. and stir for 15 min white precipitate formed. Filter the solid suck dry for 10 min and dry under vacuum dry oven at 45 °C to 50 °C. Compound 2 obtained as a white solid with 75% yield.

Synthesis of formula 3 compound - 2,2'-((l-(Dodecylamino)-l-oxopropau-2-yl)azaDediy])diacetamide
Figure 4 depicts the reaction scheme for the synthesis of formula 3 compound as per the current invention.
Experimental procedure for Synthesis of formula 3 compound:
Charge alanine (1 eq.) into a clean and dry B flask. Charge THF 3 vol. and stir for 10 min under nitrogen at room temperature to get uniform solution. Charge triethylamine (2.1 eq.) into the reaction mass under nitrogen atmosphere and stir for 10 min. add chloroacetamide (2.1 eq.) portion wise at room temperature under nitrogen atmosphere. Raise the temperature 70 °C and stir for 6 h. Monitor the reaction by TLC after the ensuring the completion of reaction allow the reaction mass to cool to room temperature add (CDI 1.1 eq.) and stir for 4 h at 70 °C under nitrogen atmosphere. Check TLC after completion of the reaction allow the reaction mass to cool to room temperature. Add dodecylamine (1 eq.) and stir for 6 h at 70 oC under nitrogen atmosphere. Progress of the reaction was monitored by TLC, water 5 vol. and stir for 15 min white precipitate formed. Filter the solid suck dry for 10 min and dry under vacuum dry oven at 45 °C to 50 °C. Compound 3 obtained as a white solid with 70% yield.
Synthesis of formula 4 compound - 2,2'-((3-(Dodecylamino)-3-oxopropyl) azanediyl)diacetamide:
Figure 5 depicts the reaction scheme for the synthesis of formula 4 compound as per the current invention
Experimental procedure for Synthesis of formula 4 compound
Charge beta-alanine (1 eq.) into a clean and dry B flask. Charge THF 3 vol. and stir for 10 min under nitrogen at room temperature to get uniform solution. Charge triethylamine (2.1 eq.) into the reaction mass under nitrogen atmosphere and stir for 10 min. add chloroacetamide (2.1 eq.) portion wise at room temperature under nitrogen atmosphere. Raise the temperature 70 oC and stir for 6 h. Monitor the reaction by TLC after the ensuring the completion of reaction allow the reaction mass to cool to room temperature add (CDI 1.1 eq.) and stir for 4 h at 70 °C under nitrogen atmosphere. Check TLC after completion of the reaction allow the reaction mass to cool to room temperature. Add dodecylamine (I eq.) and stir for 6 h at 70 oC under nitrogen

atmosphere. Progress of the reaction was monitored by TLC, water 5 vol. and stir for 15 min white precipitate formed. Filter the solid suck dry for 10 min and dry under vacuum dry oven at 45 °C to 50 °C. Compound 4 obtained as a white solid with 70% yield.
Flotation experiments: The reagents synthesized as per the current invention were tested for their efficiency for separating the silica and alumina from low grade iron ore.
Floatation cell was switched on, and 1000 ml water was poured in to the floatation cell. About 500 gm of feed sample was then added to the floatation cell and pH was maintained between 7-9.5 by adding NaOH drop wise. After 5mins of conditioning the depressant (causticized starch in the order of 500 to 1000 ppm) was added. Thereafter the synthesized collectors as per the current inventions were added (500-1000 ppm) and the sample was conditioned for 3-5mins. Thereafter frother (Methyl isobutyl carbinol, 200 ppm) was added. Thereafter, air valve was opened and the material was raked off after at 30secs interval each till the 5th or 6th material comes out. The collected materials were termed as froth 1, froth2 and so on. The left over material in the flotation cell is the concentrate. The products were dried, weighed and sent for chemical analysis.
Results
Flotation experiments were carried out with 500 g of iron ore sample (size: -200#, mesh) using
the synthesized reagents as collectors. The feed alumina and silica was in the range of 2%-4%. In all the flotation experiments, two fragments were collected as froth and tailings. In a reverse flotation system, the froth is the impurity and the product which remains behind in the flotation cell is called the concentrate or tailing. The reagents developed produced a concentrate widi alumina and silica in the range of 1.2%-2.8% with a yield of more than 70%.

We claim:
1. A compound of formula-I

R =Alkylchalns (C6. C8. C12)
Figure: 1
wherein, 'R' is an alkyl group or alkyl attached to amide having carbon atoms ranging from C6 to C12
2. The compound as claimed in claim I, wherein the compound of formula-l is 2,2'-(Tridecy lazanediyl)diacetamide

3. The compound as claimed in claim l, wherein the compound of formula-2 is Dodecyl bis(2-amino-2-oxoethyl) glycinate.


4, The compound as claimed in claim 1, wherein the compound of formula-3 is
2,2'-((l-(Dodecylamino)-l-oxopropan-2-yl)azanediyl)diacetamide

5. The compound as claimed in claim 1, wherein the compound of formula-4 is 2,2'-((3-
(DodecyIamino)-3-oxopropyl)azanediyl)diacetamide

6, A process of preparing the compound of formula-I as claimed in claim 1, comprising steps of-
subjecting an alkylamine to N, N- dialkylation reaction with chloroacetamide in a solvent using a base (triethylamine, sodium hydroxide and pyridine) at 70 °C under nitrogen atmosphere.

7. The process as claimed in claim 1, wherein the solvent is selected from a group consisting of tetrahydrofuran, acetonitrile, dichloromethane and ethyl acetate.
8. The process as claimed in claim 1, wherein the alkylamine is selected from a group consisting of hexylamine, octylamine and dodecylamine.
9. The process as claimed in claim 1, wherein the process of preparing formula 1 compound - 2,2'-(Tridecylazanediyl)diacetamide comprises the steps of-
Reacting dodecylamine with triethylamine and chloroacetamide in solvent tetrahydrofuran (THF) at 70 °C under nitrogen atmosphere.
Ref. Figure 2
10. The process as claimed in claim 1, wherein the process of preparing formula 2
compound - Dodecyl bis(2-amino-2-oxoethyl) glycinate comprises the steps of-
Mixing glycine with tetrahydrofuran (THF) under nitrogen at room temperature to get
uniform solution;
Charging triethylamine into the reaction mass comprising glycine and tetrahydrofuran
under nitrogen atmosphere;
adding chloroacetamide into the reaction mass comprising glycine, tetrahydrofuran and
triethylamine at room temperature under nitrogen atmosphere;
Raising the temperature 70 °C and stir for 6 hour;
Allowing the reaction mass 2A to cool to room temperature add Carbonyldiimidazole
(CDI) and stiring for 4 h at 70 oC under nitrogen atmosphere; and
Allowing the reaction mass 2B to cool to room temperature and adding dodecylamine
and stir for 6 h at 70 °C under nitrogen atmosphere.
Ref. Figure 3

11. The process as claimed in claim 1, wherein the process of preparing formula 3
compound - 2,2'-((l-(Dodecylamino)-l-oxopropan-2-yl)azanediyl)diacetamide
comprises the steps of-
Mixing alanine with tetrahydrofuran (THF) under nitrogen at room temperature to get
uniform solution;
Charging triethylamine into the reaction mass comprising glycine and tetrahydrofuran
under nitrogen atmosphere;
adding chloroacetamide into the reaction mass comprising glycine, tetrahydrofuran and
triethylamine at room temperature under nitrogen atmosphere;
Raising the temperature 70 °C and stir for 6 hour;
Allowing the reaction mass 3A to cool to room temperature add Carbonyldiimidazole
(CDI) and stiring for 4 h at 70 oC under nitrogen atmosphere; and
Allowing the reaction mass 3B to cool to room temperature and adding dodecylamine
and stir for 6 h at 70 °C under nitrogen atmosphere.
Ref. Figure 4
12. The process as claimed in claim 1, wherein the process of preparing formula 4
compound termed 2,2'-((3-(Dodecylamino)-3-oxopropyl)azanediyl)diacetamide
comprises the steps of-
Mixing beta-alanine with tetrahydrofuran (THF) under nitrogen at room temperature to
get uniform solution;
Charging triethylamine into the reaction mass comprising glycine and tetrahydrofuran
under nitrogen atmosphere;
adding chloroacetamide into the reaction mass comprising glycine, tetrahydrofuran and
triethylamine at room temperature under nitrogen atmosphere;
Raising the temperature 70 °C and stir for 6 hour;
Allowing the reaction mass 4A to cool to room temperature add Carbonyldiimidazole
(CDI) and stiring for 4 h at 70 oC under nitrogen atmosphere; and
Allowing the reaction mass 4B to cool to room temperature and adding dodecylamine
and stir for 6 h at 70 °C under nitrogen atmosphere.