Water resistance additive for particulate ammonium nitrate-fuel oil (ANFO) explosives
AssigneeClariant International Ltd.
InventorsMichael Feustel, Matthias Krull, Ian James Tolliday, Christopher Robin Collins, Maja Franjic, Thomas Roy
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Abstract
The present invention provides for the use of at least one oil soluble polymer comprising linear polymethylene sequences with an average of 10 to 40 consecutive methylene groups to improve the water resistance of an explosive composition comprising particulate ammonium nitrate and a fuel oil, said linear polymethylene sequences with in average 10 to 40 consecutive methylene groups may be either in the main chain or in the side chains of the oil soluble polymer.
Claims33
A process for improving the water resistance of a particulate ammonium nitrate fuel oil explosive, comprising the step of adding a fuel oil containing at least one oil soluble polymer, to an explosive composition comprising at least one particulate ammonium nitrate, wherein
- the particulate ammonium nitrate fuel oil explosive is not in the form of an emulsion and comprises less than 2 wt.-% of water, and
- the at least one oil soluble polymer is
- a copolymer (i) of ethylene and at least one vinyl ester, acrylic ester, methacrylic ester, and/or alkyl vinyl ether, wherein the copolymer (i) has linear polymethylene sequences with an average length PS(i) of 12 to 40 consecutive methylene groups, the average length PS(i) being calculated according to the formula
- PS
-
- (
- i
- )
- =
- (
- molar
-
-
- content
-
-
- of
-
-
- ethylene
- molar
-
-
- content
-
-
- of
-
-
- comonomer
- )
- *
- 2
- +
- 1
- or
- a homo- or co-polymer (ii) of esters, amides, and/or imides of ethylenically unsaturated carboxylic acids, wherein the homo- or co-polymer (ii) has linear polymethylene sequences with an average length PS(ii) of 12 to 40 consecutive methylene groups, the average length PS(ii) being calculated according to the formula
- PS
-
- (
- ii
- )
- =
- m
- 1
- ·
- ∑
- i
-
- w
- 1
-
- i
- ·
- n
- 1
-
- i
- +
- m
- 2
- ·
- ∑
- j
-
- w
- 2
-
- j
- ·
- n
- 2
-
- j
- +
- …
- +
- m
- g
- ·
- ∑
- p
-
- w
- gp
- ·
- n
- gp
- wherein
- m1, m2, . . . mg are the molar fractions of the comonomers in the polymer and the sum of the molar fractions m1 to mg=1,
- w1i, w2j, . . . wgp are the proportions by weight of the individual chain lengths i, j, . . . p of the alkyl radicals of the different comonomers 1 to g, and
- n1i, n2j, . . . ngp are the chain lengths i, j, . . . p of the alkyl radicals of the comonomers 1 to g,
- wherein terminating methyl groups of alkyl residues are included in the chain lengths of the alkyl residues;
- and
- wherein an amount of the at least one oil soluble polymer added to the explosive composition is 0.05 to 5.0 wt.-% of the weight of the at least one particulate ammonium nitrate in the explosive composition.
Dependencies are inferred from the claim text.