On-site mixed water gel explosive

Abstract

The invention discloses an on-site mixed water-gel explosive which comprises the following components in percentage by weight: 45-70% of ammonium nitrate; 9%-15% of water; 10-20% of calcium nitrate; 7-20% of liquid fuel; 0-10% of an auxiliary combustible agent; 0.7%-1.0% of a gelling agent; 0.2%-0.5% of an additive; 0.02%-8% of a sensitizing agent; 1-3% of a cross-linking agent; the density range of the explosive is 0.3-1.25 g / cm < 3 >, and the adjusting range is wide; the detonation velocity of the explosive is 2000-4500 m / s, and the explosive is high in matching degree with medium soft rock; the explosive has good water resistance and is suitable for charging of wet holes, water holes and slurry holes; the production raw materials of the explosive do not contain high-energy materials, and the prepared thickening mother liquor and semi-finished products have the characteristics of good stability, long storage life, high transportation safety and high intrinsic safety.

Description

Technical Field

[0001] The invention relates to the technical field of explosive manufacturing, in particular to an on-site mixed water gel explosive. Background Art

[0002] The main types of explosives mixed on site in my country are ammonium oil and emulsion. However, the ammonium oil explosives mixed on site are not water resistant and have a single density. At the same time, the density adjustment range of the emulsion explosives mixed on site is small, which is suitable for blasting rocks with medium hardness or above. However, large open-pit coal mines are mainly soft rocks, and there is a lack of low-density and low-detonation-velocity mixed explosives that match them.

[0003] At present, water-gel explosives have a unique gel structure system, good integrity of the explosives and good water resistance. Maxim Company abroad has a large scale of on-site mixed water-gel explosives application. However, domestic water-gel explosives are all packaged explosives, produced with methylamine nitrate as the main raw material. Methylamine nitrate is a strong oxidant and irritant compound with strong corrosiveness and is a flammable substance. There are great safety risks in the production process. Summary of the invention

[0004] The invention aims to provide a low-density, low-detonation-velocity on-site mixed water gel explosive that matches soft rock, in view of the current domestic blank of on-site mixed water gel explosive.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A field mixed water gel explosive, comprising the following components by weight percentage:

[0007] Ammonium nitrate: 45-70%;

[0008] Water: 9-15%;

[0009] Calcium nitrate: 10-20%;

[0010] Liquid fuel: 7-20%;

[0011] Auxiliary combustible agent: 0-10%;

[0012] Gelling agent: 0.7-1.0%;

[0013] Additives: 0.2-0.5%;

[0014] Sensitizer: 0.02~8%;

[0015] Cross-linking agent: 1-3%;

[0016] The ammonium nitrate ion state and the porous granular molecular state coexist in the explosive.

[0017] The on-site mixed water gel explosive of the present invention not only fills the problem of lack of low-density, low-detonation-velocity on-site mixed explosive varieties matching soft rocks, but also does not use high-energy materials such as methylamine nitrate commonly used in the prior art for production, thereby improving the inherent safety of the production process.

[0018] Furthermore, in terms of weight percentage, the ammonium nitrate in the ammonium nitrate is in an ionic state of 10-70%, and the ammonium nitrate in a porous granular state is 30-90%.

[0019] 10% to 70% of the total mass of ammonium nitrate is mixed with water, calcium nitrate and liquid fuel for dissolution, and then a gelling agent is added to obtain a thickened mother liquor. The remaining ammonium nitrate is added to the thickened mother liquor in the form of porous granular ammonium nitrate to obtain a semi-finished product. Part of the ammonium nitrate exists in the explosive in the form of porous granular molecules. The complete dissolution of the ammonium nitrate will lead to a higher crystallization point of the explosive, and crystallization is likely to occur at room temperature. During on-site use, the precipitated crystals will cause excessive pressure in the delivery pump, which is not conducive to on-site production and use. The present invention uses porous ammonium nitrate in the form of molecules in the explosive, and avoids the safety problem that may occur due to excessive pressure in the delivery pump at the site without affecting the performance of the explosive. Secondly, the method can control the density of the semi-finished product, which is conducive to the subsequent control of the density of the explosive.

[0020] Furthermore, the liquid fuel is ethylene glycol.

[0021] Furthermore, the auxiliary combustible agent is at least one of husk powder, straw powder and corn cob powder.

[0022] The combustible agents such as ethylene glycol, rice husk powder, straw powder, corn cob powder, etc. used in the present invention are renewable resources, and the product is more environmentally friendly.

[0023] Furthermore, the gelling agent is at least one of guar gum, sesbania gum and polyacrylamide.

[0024] Under the action of the cross-linking agent, the gelling agent can be bonded and cross-linked to form a stable molecular structure in the form of a network.

[0025] Furthermore, the additive is urea.

[0026] Urea plays a role in lowering the crystallization point of ammonium nitrate.

[0027] Furthermore, the sensitizer is a mixed solution of sodium thiocyanate, sodium nitrite and water.

[0028] The sensitizer contains 20% sodium nitrite, 8% sodium thiocyanate and the balance water. The charge density can be adjusted by changing the amount of sensitizer added. The density range is 0.3-1.25 g / cm 3 .

[0029] Furthermore, the cross-linking agent is a mixed solution of sodium dichromate, phosphoric acid and water.

[0030] The cross-linking agent comprises 7% sodium dichromate, 5% phosphoric acid and the balance water.

[0031] Furthermore, the chemical formula of calcium nitrate is Ca(NO 3 ) 2 ·4H 2 O is an auxiliary oxidant.

[0032] The calcium nitrate acts as an auxiliary oxidant and reduces the crystallization point of ammonium nitrate. Reducing the crystallization point of ammonium nitrate can prevent ammonium nitrate from crystallizing under low temperature conditions, improve the stability of water gel explosives, and further improve the water resistance of explosives.

[0033] Compared with the prior art, the beneficial effect of the present invention is that it fills the gap in the current on-site mixed water gel explosives suitable for soft rocks. The on-site mixed explosives disclosed by the present invention do not contain high-energy materials in the production process, have high intrinsic safety, have good water resistance, are suitable for charging in wet holes, water holes and mud holes, and use renewable resources as raw materials, so the product is more environmentally friendly. Finally, the on-site mixed explosives disclosed by the present invention can adjust the charging density according to the addition amount of the sensitizer, and the detonation velocity can be adjusted within the range of 2000m / s to 4500m / s, which has good matching with soft rocks and medium-hard rocks. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0035] Example 1

[0036] The formula composition is as follows: ammonium nitrate: 630kg; water: 130kg; calcium nitrate: 110kg; ethylene glycol: 120kg; guar gum: 7kg; rice husk powder: 10kg; urea: 3kg;

[0037] During production, 380 kg of ammonium nitrate is mixed and dissolved with calcium nitrate, water and additives out of 630 kg of ammonium nitrate, and then a gelling agent and rice husk powder are added to prepare a thickening mother liquor. The remaining 250 kg is porous granular ammonium nitrate. The porous granular ammonium nitrate and the thickening mother liquor are evenly mixed to obtain a semi-finished product.

[0038] The sensitizer formula (calculated by sensitizer weight percentage) is as follows:

[0039] Sodium nitrite: 20%

[0040] Sodium thiocyanate: 8%

[0041] Residual water

[0042] The cross-linking agent formula (calculated by cross-linking agent weight percentage) is as follows:

[0043] Sodium dichromate: 7%

[0044] Phosphoric acid: 5%

[0045] Residual water

[0046] The above formula was used to prepare the densities of 0.3, 0.7, 1.0, and 1.25 g / cm 3 The formula composition and performance of four density on-site mixed explosives are shown in Table 1.

[0047] Table 1 Explosive formula composition and performance

[0048]

[0049]

[0050] The cross-linking conditions of the explosives are shown in Table 2.

[0051] Table 2 Explosive cross-linking

[0052]

[0053] Example 2

[0054] The formula composition is as follows:

[0055] Ammonium nitrate: 630kg; Water: 130kg; Calcium nitrate: 110kg; Ethylene glycol: 120kg; Guar gum: 7kg; Husk powder: 10kg; Urea: 3kg;

[0056] During production, 420 kg of ammonium nitrate is mixed and dissolved with calcium nitrate, water and additives in 630 kg of ammonium nitrate, and then a gelling agent and rice husk powder are added to prepare a thickening mother liquor. The remaining 210 kg is porous granular ammonium nitrate; the porous granular ammonium nitrate and the thickening mother liquor are evenly mixed to obtain a semi-finished product.

[0057] The sensitizer formula (calculated by weight percentage) is as follows:

[0058] Sodium nitrite: 10%

[0059] Sodium thiocyanate: 4%

[0060] Residual water

[0061] The crosslinking agent formula (calculated by weight percentage) is as follows:

[0062] Sodium dichromate: 7%

[0063] Phosphoric acid: 5%

[0064] Residual water

[0065] The above formula was used to prepare the densities of 0.3, 0.7, 1.0, and 1.25 g / cm 3 The formula composition and performance of four density on-site mixed explosives are shown in Table 3.

[0066] Table 3 Explosive formula composition and performance

[0067]

[0068] The cross-linking conditions of the explosives are shown in Table 4.

[0069] Table 4 Explosive cross-linking conditions

[0070]

[0071] Example 3

[0072] The formula composition is as follows:

[0073] Ammonium nitrate: 575kg; Water: 130kg; Calcium nitrate: 160kg; Ethylene glycol: 115kg; Rice husk powder: 10kg; Guar gum: 7kg; Urea: 3kg;

[0074] During production, 350 kg of ammonium nitrate is mixed and dissolved with calcium nitrate, water and additives out of 575 kg of ammonium nitrate, and then a gelling agent and rice husk powder are added to prepare a thickening mother liquor. The remaining 225 kg is porous granular ammonium nitrate. The porous granular ammonium nitrate and the thickening mother liquor are evenly mixed to obtain a semi-finished product.

[0075] The sensitizer formula (calculated by weight percentage) is as follows:

[0076] Sodium nitrite: 20%

[0077] Sodium thiocyanate: 8%

[0078] Residual water

[0079] The crosslinking agent formula (calculated by weight percentage) is as follows:

[0080] Sodium dichromate: 3.5%

[0081] Phosphoric acid: 2.5%

[0082] Residual water

[0083] The above formula was used to prepare the densities of 0.3, 0.7, 1.0, and 1.25 g / cm 3 The formula composition and performance of four density on-site mixed explosives are shown in Table 5.

[0084] Table 5 Explosive formula composition and performance

[0085]

[0086] The cross-linking speed of explosives is shown in Table 6.

[0087] Table 6 Explosive cross-linking conditions

[0088]

[0089] It can be seen from the experimental data of the aforementioned embodiments that, when the amount of cross-linking agent is constant, as the content of sensitizer decreases, the density of the charge increases, which will increase the detonation velocity of the prepared explosive and is adjustable within the range of 2000 to 4500 m / s. Under the same charge density, the detonation velocity can also be adjusted, that is, the water-gel explosive of the present invention can meet the use requirements of low density and low detonation velocity for soft rocks, and has good compatibility with soft rocks and medium-hard rocks. The formula ratio of the cross-linking agent used in the explosive formula can also be adjusted as needed to meet the requirements of the cross-linking speed of the explosive. According to the above embodiments, when the amount of cross-linking agent added is constant, the ratio change in the added cross-linking agent will affect the cross-linking speed of the explosive. An increase in the ratio of sodium dichromate will increase the cross-linking speed of the explosive, thereby meeting the performance adjustment requirements for the water-gel explosive.

[0090] What is disclosed above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A field mixed water gel explosive, characterized in that: By weight percentage, it includes the following components: Ammonium nitrate: 45-70%; Water: 9-15%; Calcium nitrate: 10-20%; Liquid fuel: 7-20%; Auxiliary combustible agent: 0-10%; Gelling agent: 0.7-1.0%; Additives: 0.2-0.5%; Sensitizer: 0.02~8%; Cross-linking agent: 1-3%; The ammonium nitrate coexists in the explosive in an ionic state and a porous granular molecular state.

2. The on-site mixed water gel explosive as claimed in claim 1, characterized in that: Calculated by weight percentage, in ammonium nitrate, ionic ammonium nitrate accounts for 10-70%, and porous granular ammonium nitrate accounts for 30-90%.

3. The on-site mixed water gel explosive as claimed in claim 1, characterized in that: The liquid fuel is ethylene glycol.

4. The on-site mixed water gel explosive as claimed in claim 1, characterized in that: The auxiliary combustible agent is at least one of husk powder, straw powder and corn cob powder.

5. The on-site mixed water gel explosive as claimed in claim 1, characterized in that: The gelling agent is at least one of guar gum, sesbania gum and polyacrylamide.

6. The on-site mixed water gel explosive as claimed in claim 1, characterized in that: The additive is urea.

7. The on-site mixed water gel explosive as claimed in claim 1, characterized in that: The sensitizer is a mixed solution of sodium thiocyanate, sodium nitrite and water.

8. The on-site mixed water gel explosive as claimed in claim 1, characterized in that: The cross-linking agent is a mixed solution of sodium dichromate, phosphoric acid and water.

9. The method for preparing on-site mixed water gel explosive according to claim 1, characterized in that: The chemical molecular formula of the calcium nitrate is Ca(NO3)2·4H2O, and it is an auxiliary oxidant.

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