A method for preparing small batch samples of on-site mixed porous granular ammonium nitrate oil explosive

Abstract

The invention discloses a method for preparing small batch samples of a field mixed porous granular ammonium nitrate oil-fuel explosive, comprising utilizing field mixing equipment, adding a coloring agent to an oil phase material and mixing the dyed oil phase material with porous granular ammonium nitrate under normal production conditions, ensuring that part of the granular material is not dyed, and then randomly collecting the field samples after mixing; obtaining the percentage of the field sample dyed and undyed porous granular ammonium nitrate in the sample amount through statistical analysis and calculation, and defining one of the ratios as an evaluation index of the mixing effect; finally, preparing small batch samples of the same mixing effect using an experimental mixer in a laboratory. The invention has the beneficial effects of being able to quickly and reliably reproduce the mixing ability of the field equipment in the laboratory, solving the problems of a large number of samples obtained by the existing method, large waste, and high cost, and effectively avoiding blind production and causing losses or unnecessary safety risks.

Description

Technical Field

[0001] The invention relates to a laboratory preparation technology of porous granular ammonium nitrate oil explosive, in particular to a small batch sample preparation method of on-site mixed porous granular ammonium nitrate oil explosive. Background Art

[0002] On-site mixed porous granular ammonium nitrate oil explosive is a granular explosive mixture composed of porous ammonium nitrate particles and fuel oil. It is mainly suitable for open-air blasting projects and blasting projects without the risk of methane and mine dust explosions. Among them, fuel oil mainly includes diesel, coal-to-liquids, engine oil, etc. On-site mixing is usually carried out by an on-site mixing vehicle. The porous ammonium nitrate particles and fuel oil are respectively transported to the mixing tank in proportion. After mixing at a set speed and a specified time, they are directly transported to the blasthole. To ensure the quality of the explosives and the blasting effect, it is usually necessary to inspect the raw materials before determining the mixing parameters, and to conduct blasting tests on the mixed explosive samples at the blasting site or under the same or similar rock conditions as the blasting site to verify the explosion effect.

[0003] The existing sample preparation technology for explosives, due to the lack of an evaluation index for evaluating the mixing effect of explosives, can only make samples with the help of on-site mixing equipment, and obtain multiple samples based on different process parameters, and determine the applicable stirring parameters of the oil phase material based on the explosion effect. If the oil phase material changes, the sample needs to be re-prepared and the blasting test repeated. Due to the volume limitation of on-site equipment, small batches of samples cannot be made, resulting in a large number of samples, which is a huge waste, increases the cost of blasting operations, and also increases the risk of blasting quality. Similarly, due to the lack of an evaluation index for the mixing effect, the most commonly used quality inspection method for porous granular ammonium nitrate in the existing technology is to test the oil absorption rate of porous granular ammonium nitrate. The testing method is to judge the oil absorption rate by the change in weight after the porous granular ammonium nitrate is mixed with the oil phase material. This test method has the following significant drawbacks: First, the mixing time is long. Mixing is typically done manually or with the aid of simple tools, typically taking around 10 minutes. In actual production, mixing times are typically less than 30 seconds. Second, during testing, the porous ammonium nitrate granules are immersed in an oil-phase material. The volume ratio of the porous ammonium nitrate granules to the oil-phase material (e.g., diesel) differs significantly from the actual production ratio. During testing, the volume ratio is typically around 1.5:1. In actual production, the oil-phase material is sprayed onto the porous ammonium nitrate granules, and the volume ratio is typically around 20:1. This difference in volume ratios makes it difficult to truly reflect the actual production process, leading to distorted results. Based on experience, this test result only demonstrates impracticality, not feasibility, and cannot provide guidance for production. Therefore, it is necessary to develop an evaluation metric that can reliably replicate actual mixing results. This evaluation metric can be used to evaluate the conformity of small batches of samples or raw materials during sample preparation and / or raw material testing.

[0004] It is generally believed that the more uniform the dispersion of the oil phase material and the porous granular ammonium nitrate, the better the performance of the explosive. Therefore, by introducing a visual color difference, the degree of dispersion of the oil phase material in the porous granular ammonium nitrate can be quantitatively expressed.

[0005] And in actual production practice, the production parameter of certain mixed loading equipment (ammonium oil mixed loading vehicle) is relatively fixed as oil inlet, number of nozzles, nozzle position, mixing time, promptly can be understood as the mixing ability of this equipment is setting, promptly the uniformity effect that mixed back porous granular ammonium nitrate mixes with oil phase material is definite.If this mixing ability is quantified by indexability calibration, reuse miniaturized mixing equipment such as kitchen blender, adopt small batches (generally less than 1kg) to mix the product of same ability index, the mixing ability of this equipment can be reproduced quickly and reliably, can avoid blindly or based on the erroneous conclusion that existing method obtains, produce and cause loss or unnecessary safety risk.Based on this, the present invention proposes a kind of small batch sample preparation method of on-site mixed porous granular ammonium nitrate oil-fuel mixture. Summary of the Invention

[0006] Purpose of the present invention is exactly for on-site mixed porous granular ammonium nitrate oil-fuel mixture in prior art and can only prepare sample by on-site mixed equipment deficiency, a kind of on-site mixed porous granular ammonium nitrate oil-fuel mixture small batch sample preparation method is provided, this method is by the mode of adding coloring agent in oil phase material, under on-site production condition, obtain and have dyed and undye field sample, and will dye or undye account for the ratio of total sample as the quantitative evaluation index of mixing effect evaluation, then, based on identical evaluation index, utilize experimental stirrer to carry out small batch preparation sample.Thus solving and utilizing field equipment to make sample quantity is large, causes waste large, cost is high, and has the problem of blasting quality risk.

[0007] To achieve the aforementioned objectives, the present invention adopts the following technical solutions.

[0008] A method for preparing small batch samples of on-site mixed porous granular ammonium nitrate oil explosive comprises the following steps:

[0009] The first step is on-site sample collection: using on-site mixing equipment, an appropriate amount of dye is added to the oil phase material and mixed evenly. Under normal production conditions, the dyed oil phase material is mixed with porous granular ammonium nitrate. Under conditions that ensure that some of the porous granular ammonium nitrate is not dyed, the mixed explosives are randomly collected as on-site samples;

[0010] The second step is to set the mixing effect evaluation index: randomly extract a set amount of the field samples, and obtain the percentage ratio of the amount of dyed and undyed porous granular ammonium nitrate in the field samples to the amount of the extracted samples through statistical analysis and calculation, and define the ratio of dyed and undyed porous granular ammonium nitrate as the mixing effect evaluation index of the mixed explosive;

[0011] The third step is sample preparation: In a laboratory environment, using an experimental mixer, the same porous granular ammonium nitrate as used at the production site and the oil phase material with the same dye ratio and mixed are mixed, and small batch samples with the same mixing effect are obtained by adjusting the stirring parameters.

[0012] The small-batch sample preparation method of the present invention, which adopts the aforementioned scheme, obtains field samples with both dyed and undyed materials under on-site production conditions by adding a dye to the oil phase material. The ratio of dyed to undyed materials to the total sample is set as a quantitative indicator for evaluating mixing ability. Using miniaturized laboratory mixing equipment to mix explosives with the same mixing effect, the mixing ability of the field equipment can be quickly and reliably reproduced in the laboratory. Using small-batch samples obtained in the laboratory replaces the existing technology that relies solely on field equipment to prepare samples, resulting in large quantities, waste, and high costs. It also effectively avoids blind production or production based on erroneous conclusions drawn from existing raw material testing methods, which can cause losses or unnecessary safety risks. In actual applications, the ratio of undyed materials to the total amount, also known as the undyed rate or white rate, is used as an evaluation indicator. By collecting and analyzing on-site mixing equipment parameters, the mixing ability of equipment with a white rate of 14% under existing conditions is determined. When the white rate of the mixed explosive after mixing is lower than or equal to 14%, the evaluation index requirements are met, that is, the mixing effect is good or qualified; when it is greater than 14%, the evaluation index requirements are not met, that is, the mixing effect is not good or unqualified.

[0013] Preferably, in the first step, the ratio of the dye to the oil phase material, calculated as a mass percentage, is 0.01‰ to 2‰; and the dye is selected from Sudan Red, Oily Green, or Oily Emerald Green, so as to provide a variety of dyeing options while allowing for distinguishable dyeing effects.

[0014] More preferably, the dye is Sudan Red, and the ratio is 0.1‰ to 1‰, so as to obtain a more striking color differentiation effect, facilitate accurate differentiation and recognition by visual recognition technology, and improve the accuracy of the judgment result.

[0015] Preferably, in the second step, the number of the dyed and undyed porous granular ammonium nitrate is counted by weight, by the number of particles, or by area using image recognition technology within a predetermined area. This allows basic data to be obtained through a variety of statistical methods, facilitating selection or cross-comparison to verify the accuracy of the results.

[0016] Preferably, the stirring parameters include stirring speed, stirring volume ratio to allowable stirring volume, stirring duration, and oil-phase material addition time; wherein the oil-phase material addition time includes the addition moment and duration. By varying various parameters, the on-site mixing effect can be accurately reproduced, minimizing the differences between laboratory-prepared samples and on-site samples, thereby achieving the goal of accurately reproducing on-site samples.

[0017] Preferably, the experimental blender is constructed from a kitchen blender and utilizes a plastic whisk head for stirring. The plastic whisk head has a symmetrical blade structure with a fence-like structure, and the blades extend outward in an arc from the stirring shaft. This facilitates market procurement, reduces experimental conditions, and reduces experimental costs by utilizing the characteristics of small household appliances with high power consumption and low price.

[0018] The beneficial effect of the present invention is that by adding a dye in an appropriate proportion to the oil phase material and using the dyeing ratio of the mixed particles as a quantitative indicator for evaluating the mixing effect, and then using a laboratory mixer to prepare small batches of samples, the mixing capacity of the on-site equipment can be quickly and reliably reproduced in the laboratory. The small batch samples obtained in the laboratory replace the shortcomings of the existing technology that can only rely on on-site equipment to prepare samples, resulting in large quantities, large waste and high costs. It can also effectively avoid blind production or production based on erroneous conclusions obtained based on existing raw material detection methods, which may cause losses or unnecessary safety risks. DETAILED DESCRIPTION

[0019] The present invention will be further described below, but the present invention is not limited to the scope of the embodiments described.

[0020] A method for preparing small batch samples of on-site mixed porous granular ammonium nitrate oil explosive comprises the following steps:

[0021] The first step is on-site sample collection: using on-site mixing equipment, an appropriate amount of dye is added to the oil phase material and mixed evenly. Under normal production conditions, the dyed oil phase material is mixed with porous granular ammonium nitrate. Under conditions that ensure that some of the porous granular ammonium nitrate is not dyed, the mixed explosives are randomly collected as on-site samples;

[0022] The second step is to set the mixing effect evaluation index: randomly extract a set amount of the field samples, and obtain the percentage ratio of the amount of dyed and undyed porous granular ammonium nitrate in the field samples to the amount of the extracted samples through statistical analysis and calculation, and define the ratio of dyed and undyed porous granular ammonium nitrate as the mixing effect evaluation index of the mixed explosive;

[0023] The third step is sample preparation: In a laboratory environment, using an experimental mixer, the same porous granular ammonium nitrate as used at the production site and the oil phase material with the same dye ratio and mixed are mixed, and small batch samples with the same mixing effect are obtained by adjusting the stirring parameters.

[0024] In the first step, the ratio of the dye to the oil phase material is calculated as a mass percentage and is 0.01‰ to 2‰; the dye is selected from Sudan Red, Oily Green, or Oily Emerald Green. Specifically, the dye is Sudan Red; and the ratio is 0.1‰ to 1‰.

[0025] In the second step, the number of the dyed and undyed porous granular ammonium nitrate is counted by weight; or by the number of particles; or by area of an image within a set area using image recognition technology.

[0026] During the on-site sample collection process, 0.1‰ to 1‰ of Sudan Red is added to the oil tank of the on-site mixing vehicle, and then the compressor is used to pump air and stir it to mix it evenly with the oil phase material.

[0027] The oil phase material is composed of diesel. The stirring parameters include stirring speed, stirring volume ratio to allowable stirring capacity, stirring duration, and oil phase material addition time; wherein the oil phase material addition time includes the addition time and the addition duration.

[0028] In addition, the experimental blender is composed of a kitchen blender and uses a plastic whipping blade head for stirring; the plastic whipping blade head has a symmetrical blade structure with a fence-like structure, and the blade extends outward from the stirring shaft in an arc shape.

[0029] Tests have shown that using the ratio of undyed material to the total weight, also known as the undyed rate or white rate, as an evaluation indicator, and through on-site analysis of mixing equipment parameters, the mixing capacity of equipment with a white rate of 14% under existing conditions has been determined. When the white rate of the mixed explosives after mixing is less than or equal to 14%, the evaluation indicator is met, indicating good or acceptable mixing performance. When it is greater than 14%, the evaluation indicator is not met, indicating poor or unacceptable mixing performance.

[0030] In the laboratory reproduction process, the kitchen mixer specifically used was a BORAN FP3010 food mixer. Considering the mixing uniformity, a small batch of samples of about 1000 g was prepared at a time.

[0031] The experiment was carried out in a laboratory environment with a temperature of 15°C to 20°C and a humidity of about 60% to 70%, with a stirring speed of about 300 rpm. The stirring duration of the granular material was about 30 seconds. During the stirring period, the oil phase material that had been evenly mixed with the dye was added. The addition duration of the oil phase material was about 10 seconds. The on-site mixing effect evaluation index, i.e., a whiteness rate of about 14%, could be reproduced.

[0032] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. a small batch sample preparation method for on-site mixed porous granular ammonium nitrate oil explosive, characterized in that, The following steps are involved: The first step is on-site sample collection: using on-site mixing equipment, an appropriate amount of dye is added to the oil phase material and mixed evenly. Under normal production conditions, the dyed oil phase material is mixed with porous granular ammonium nitrate. Under conditions that ensure that some of the porous granular ammonium nitrate is not dyed, the mixed explosives are randomly collected as on-site samples; The second step is to set the mixing effect evaluation index: randomly extract a set amount of the field samples, and obtain the percentage ratio of the amount of dyed and undyed porous granular ammonium nitrate in the field samples to the amount of the extracted samples through statistical analysis and calculation, and define the ratio of dyed and undyed porous granular ammonium nitrate as the mixing effect evaluation index of the mixed explosive; The third step is sample preparation: In a laboratory environment, using an experimental mixer, the same porous granular ammonium nitrate as used at the production site and the oil phase material with the same dye ratio and mixed are mixed, and small batch samples with the same mixing effect are obtained by adjusting the stirring parameters.

2. The method for preparing small batch samples according to claim 1, characterized in that: In the first step, the ratio of the added amount of the dye to the oil phase material is calculated as a mass percentage, and the ratio is 0.01‰ to 2‰; the dye is composed of any one of Sudan red, oily green or oily emerald green.

3. The method for preparing small batch samples according to claim 2, characterized in that: The dye is Sudan Red; the ratio is 0.1‰ to 1‰.

4. The method for preparing small batch samples according to claim 1, wherein: In the second step, the number of the dyed and undyed porous granular ammonium nitrate is counted by weight, by the number of particles, or by using image recognition technology to count the dyed and undyed areas of images within a set area.

5. The method for preparing small batch samples according to any one of claims 1 to 4, characterized in that: The stirring parameters include stirring speed, stirring amount to allowable stirring capacity ratio, stirring duration, oil phase material addition time; wherein, the oil phase material addition time is the duration of the oil phase material addition.

6. The method for preparing small batch samples according to claim 5, characterized in that: The experimental blender consisted of a kitchen blender and utilized a plastic whisk blade for blending.

7. The method for preparing small batch samples according to claim 6, characterized in that: The plastic whipping blade head is a symmetrical blade structure with a fence structure, and the blade extends outward from the stirring shaft in an arc shape.