Low-temperature oxygen candle oxygen production grain and preparation method thereof

Abstract

The invention relates to an oxygen-producing grain of a low-temperature oxygen candle, which is an oxygen-producing grain with the density of 1.9-2.5 g / cm < 3 > prepared by uniformly dry-mixing 95.5-98.5% of a pretreated oxygen-producing source, 0.5-3.5% of a catalyst and 0.2-1% of a chlorine inhibitor, wherein the pretreatment oxygen production source is a powdery oxygen production source with the particle size being smaller than 300 microns, and the powdery oxygen production source is obtained by doping a high-thermal-conductivity carbon-based nano material with the mass being 0.2-0.65% of that of a chlorate oxygen production source into the chlorate oxygen production source. According to the oxygen production grain, a fuel-free formula is adopted, continuous and stable combustion in the low-temperature environment of-55 DEG C can be achieved, the oxygen production rate is 99% or above, the heat production amount in the combustion process is low, oxygen release is stable, extinguishment is not prone to occurring, residues are not prone to flowing after combustion, and no holes exist.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid chemical oxygen sources and relates to an oxygen-generating powder column for oxygen candles, in particular to an oxygen-generating powder column for oxygen candles capable of continuous and stable combustion in an ultra-low temperature environment and a preparation method thereof. Background Art

[0002] Oxygen candles are a solid oxygen source that produces high-purity oxygen through the catalytic decomposition of chlorates. When the candle is ignited, the chlorates decompose under the action of the catalyst to produce oxygen. Oxygen candles have significant advantages. First, the oxygen supply is stable. Once activated, they can continuously and evenly produce oxygen, providing a continuous supply of oxygen to enclosed spaces, such as mine rescue and submarine voyages. They can ensure an uninterrupted oxygen supply. Second, oxygen candles are compact and portable, freeing them from the constraints of bulky high-pressure gas cylinders. They are easy to store and transport, and can be quickly deployed in emergencies. Third, oxygen candles are extremely simple to operate, with a simple and easy-to-understand triggering method, making them quickly accessible to non-professionals. This ensures timely oxygen supply in critical moments when every second counts, becoming a solid backing for protecting lives.

[0003] The oxygen candle has an ingenious structure, integrating four major parts: ignition system, oxygen production system, filtration system and thermal insulation system. The oxygen-producing charge column, as the core of the oxygen production system, lies first in its unique chemical formula, which is composed of chlorate or perchlorate combined with catalysts and metal fuels. The precise control of fuel type, addition amount and thermal management strategy is particularly important to ensure the spontaneous and continuous supply of oxygen, so that the oxygen-producing charge column can operate safely and stably.

[0004] However, adding metal fuel to oxygen candles has the following hazards:

[0005] 1) Reduced safety. Metal fuels are generally highly reactive. When added to the oxygen-generating column of an oxygen candle, the heat generated by the combustion of the metal fuel directly increases the temperature of the candle wall. If improperly controlled, excessive heat can accumulate within the candle, increasing the risk of uncontrolled combustion of the entire device. Metals such as magnesium, aluminum, and titanium, for example, release significant amounts of heat during combustion and react violently. Even slight changes in the reaction conditions of the candle, such as a slightly elevated temperature or abnormal local oxygen concentration, can dramatically accelerate the combustion process, leading to serious safety incidents such as explosions.

[0006] 2) Harmful byproducts. The combustion of metal fuels produces byproducts such as metal oxides. For example, aluminum produces aluminum oxide. If inhaled, these metal oxide particles can damage the respiratory tract and lungs. When oxygen candles are used in enclosed spaces such as submarines and mine shelters, these harmful byproducts can pollute the air and have long-term adverse effects on human health.

[0007] 3) Stability is affected. The addition of metal fuel may affect the chemical stability of the oxygen-generating grain itself. Oxygen candles typically need to remain stable under certain temperature and humidity conditions for long-term storage and ready use. Metal fuel may chemically react with other components in the oxygen-generating grain, causing the grain to deteriorate and agglomerate during storage, thereby shortening the shelf life of the oxygen candle and reducing its reliability.

[0008] At the same time, the morphological integrity of the oxygen-producing grain after combustion plays a crucial role in the oxygen-producing process of oxygen candles. Once the morphology of the reaction products after combustion becomes uncontrolled, holes can easily form within the oxygen-producing grain, leading to a number of serious problems. During the combustion of an oxygen candle, reaction rates may vary in different locations. Slightly uneven distribution of components within the grain, or inconsistent local conditions such as temperature and oxygen concentration, can cause excessive reaction speeds in certain areas. Rapid consumption of the reactants in these areas prevents the surrounding reactants from being replenished, forming voids within the grain that eventually develop into holes. These holes act as barriers, blocking the close connection between the reaction front and the unreacted reagents, preventing them from fully contacting each other. This significantly reduces the efficiency of the chemical reaction and, in turn, significantly reduces the oxygen production rate.

[0009] In addition, the vast majority of oxygen candle products currently on the market have a significant shortcoming: they struggle to maintain stable and continuous combustion in ultra-low temperature environments. As application scenarios become increasingly diverse, the demand for oxygen in extremely cold conditions, such as polar expeditions and rescue operations in high-altitude cold regions, is becoming increasingly prominent. Whether solid oxygen candles can operate reliably in the cold becomes particularly critical. Therefore, overcoming the challenge of solid oxygen candles' low-temperature adaptability is urgent. This not only affects the performance of related equipment in extremely cold environments, but is also a key step in expanding the application boundaries of oxygen candles and ensuring the smooth progress of special missions.

[0010] CN 114906815A discloses an ultra-low-temperature nano-solid oxygen candle oxygen generator. By adding an appropriate amount of nano-iron oxide or cobalt catalyst to chlorate, the oxygen candle achieves sustained combustion in a low-temperature environment. However, the lowest combustion temperature is only -40°C. Further reduction in temperature still fails to achieve stable and sustained combustion of the oxygen-generating charge. Summary of the Invention

[0011] The purpose of the present invention is to provide a low-temperature oxygen candle oxygen-generating powder column and a preparation method thereof, so that the oxygen candle can burn stably in a lower temperature environment and the residue after combustion is not easy to flow.

[0012] To achieve the above-mentioned purpose of the invention, the low-temperature oxygen candle oxygen-generating powder column of the present invention does not use metal fuel and is prepared only from the following raw materials in percentage by weight: 95.5-98.5% of a pretreated oxygen source, 0.5-3.5% of a catalyst, and 0.2-1% of a chlorine inhibitor. The pretreated oxygen source is a powdered oxygen source with a particle size of less than 300 μm obtained by adding 0.2-0.65% by weight of a high thermal conductivity carbon-based nanomaterial to a chlorate oxygen source.

[0013] The low-temperature oxygen candle oxygen-generating powder column of the present invention can continue to burn until the oxygen release is completed in a low-temperature environment of -55°C, and has low heat generation and stable oxygen release.

[0014] Specifically, the chlorate oxygen source in the pre-treated oxygen source of the present invention is one of potassium chlorate, sodium chlorate, potassium perchlorate or sodium perchlorate, or a mixture of any proportions of the above.

[0015] More specifically, the high thermal conductivity carbon-based nanomaterial is any one of graphene, carbon nanotubes or nanographite.

[0016] The main function of adding a catalyst to the oxygen-generating powder column is to reduce the decomposition temperature of the chlorate oxygen source, thereby reducing the surface temperature of the oxygen candle. The catalyst described in the present invention is a nano-oxide catalyst of iron, cobalt, nickel or manganese.

[0017] Furthermore, the catalyst is preferably selected from one or a combination of nano-ferroferric oxide, nano-cobaltic oxide, nano-cobaltous oxide, nano-cobaltous oxide, nano-cobaltous oxide, nano-manganese dioxide or nano-nickel oxide.

[0018] Furthermore, the particle size of the catalyst in the present invention is 20-200 nm.

[0019] Furthermore, the role of adding a chlorine inhibitor is to eliminate the generated chlorine and reduce the chlorine content. The chlorine inhibitor described in the present invention is one of barium peroxide, sodium peroxide, and lithium peroxide, or a combination of several of them in any proportion.

[0020] Furthermore, the present invention also provides a method for preparing the low-temperature oxygen candle oxygen-generating powder column, which specifically comprises:

[0021] 1) adding the high thermal conductivity carbon-based nanomaterial in the proportion to the chlorate oxygen generating source, and ball milling the mixture to obtain a powdered pretreated oxygen generating source with a particle size of less than 300 μm;

[0022] 2) dry-mixing the pretreated oxygen source, the catalyst, and the chlorine inhibitor in a mixer according to the mass percentage until uniformly mixed, and then pressing into a mold;

[0023] 3) After demoulding, dry at 100-150℃ to obtain a density of 1.9-2.5g / cm3 Oxygen-producing column.

[0024] Furthermore, the present invention is preferably based on 10-15T / cm 2 The uniformly mixed raw materials are pressed into a mold under a pressure of .

[0025] Furthermore, the drying time is preferably 3-8 hours.

[0026] Highly thermally conductive carbon-based nanomaterials such as graphene, carbon nanotubes, or nanographite have very strong thermal conductivity. The present invention adds a small amount of highly thermally conductive carbon-based nanomaterials to the raw materials of the oxygen-producing powder column, enabling it to form a good heat conduction path inside the oxygen-producing powder column. Even in the absence of metal fuel, once the oxygen candle device begins to react, due to the thermal conductivity of the highly thermally conductive carbon-based nanomaterials, the local high temperature generated by the reaction can be evenly transferred to the interior of the oxygen-producing powder column in a short period of time, thereby fully utilizing the heat generated by the initial reaction to ensure the continuous and balanced progress of the reaction. Therefore, the oxygen-producing powder column of the present invention can still burn normally without using any metal fuel. Not only can the oxygen production rate reach more than 99%, but the wall temperature of the solid oxygen generator during the combustion process is also lower than 130°C.

[0027] At the same time, since no metal fuel is used, the oxygen-producing powder column of the present invention has high safety, strong reliability, low heat generation, stable oxygen release, and is not easy to extinguish. The residue after combustion is not easy to flow, and the formation of holes is avoided.

[0028] Another benefit of adding highly thermally conductive carbon-based nanomaterials to the oxygen-generating grain raw material is that, even when the ambient temperature drops to extremely low levels, the preheating effect can reduce temperature differences, ensuring full combustion of the oxygen-generating grain. Combustion experiments have shown that after freezing the oxygen-generating grain at -50°C for 24-48 hours, it continues to burn smoothly and completely, releasing oxygen in this low-temperature environment until the grain is completely burned, thus improving safety and reliability.

[0029] More importantly, the present invention further reduces the low-temperature operating temperature of the oxygen-producing charge by first preparing a pretreated oxygen-producing source with a chlorate oxygen-producing source and a high-thermal-conductivity carbon-based nanomaterial, and then compressing the oxygen-producing charge with other raw materials. The oxygen-producing charge can even be fully burned when the external ambient temperature drops to -55°C.

[0030] The present invention finds that by adding a small amount of high thermal conductivity carbon-based nanomaterials to the raw materials for preparing oxygen candle oxygen-producing powder columns, the oxygen-producing powder columns can be obtained by a dry pressing method without using any binder. The preparation process is simple and safe, and not only avoids the complex process of wet pressing the powder columns, but also avoids the problem of a certain amount of chlorine gas being generated due to incomplete drying of the wet pressing powder columns.

[0031] The present invention avoids the use of metal fuel while achieving the same oxygen release rate by adding a small amount of high-thermal-conductivity carbon-based nanomaterials to the oxygen-generating powder column, thereby increasing the proportion of chlorate oxygen-generating sources and the amount of oxygen released. When the solid oxygen candle has the same weight of oxygen-generating powder column, the oxygen release amount is greater, the heat generated is less, and the use is safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the state after combustion of the oxygen-generating charge prepared in Example 1.

[0033] Figure 2 This is a volume flow-time curve diagram of the combustion of the oxygen-producing charge prepared in Example 2.

[0034] Figure 3 This is a volume flow-time curve diagram of the combustion of the oxygen-generating charge prepared in Comparative Example 2.

[0035] Figure 4 This is the condition after combustion of the oxygen-generating charge prepared in Comparative Example 3. DETAILED DESCRIPTION

[0036] The following embodiments of the present invention are further described in detail with reference to the accompanying drawings and examples. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention so that those skilled in the art can fully understand and utilize the present invention.

[0037] However, the present invention can be implemented in many other ways different from those described in the following embodiments, and those skilled in the art can also make similar improvements without violating the connotation of the present invention. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0038] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art. The terms used in the present invention specification are only for describing specific embodiments and are not intended to limit the present invention.

[0039] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] The terms "multiple", "multiple", "multiple times", "multiple groups", etc. used in the present invention, unless otherwise specified, refer to a quantity greater than or equal to 2; "above" includes the number itself, such as "more than two" includes two, three or more.

[0041] The term "preferably" used in the present invention is only used to describe an implementation method or example with better effects, and does not constitute a limitation on the scope of protection of the present invention.

[0042] The production processes, experimental methods or detection methods involved in the embodiments of the present invention, unless otherwise specified, are conventional methods in the prior art, and their names and / or abbreviations are conventional names in the field and are very clear and unambiguous in the relevant fields of use. Those skilled in the art can understand the conventional process steps based on the names and apply the corresponding equipment, and implement them according to conventional conditions or conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0043] The various instruments, equipment, raw materials or reagents used in the embodiments of the present invention are not particularly limited in their sources and are all conventional products that can be purchased through regular commercial channels or prepared according to conventional methods well known to those skilled in the art.

[0044] In the embodiment of the present invention, the following method is specifically used to prepare the low-temperature oxygen candle oxygen-generating powder column:

[0045] 1) Add 0.2-0.65% of the mass of high thermal conductivity carbon-based nanomaterials to the chlorate oxygen source, mix them by ball milling, and pass them through a 50-mesh sieve to obtain a powdered pretreated oxygen source with a particle size of less than 300 μm;

[0046] 2) According to the mass percentage, the pre-treated oxygen source is 95.5-98.5%, the catalyst is 0.5-3.5%, and the chlorine inhibitor is 0.2-1%. The pre-treated oxygen source, catalyst and chlorine inhibitor are dry-mixed in a mixer, poured into a custom mold, and pressed on a tablet machine at a speed of 10-15T / cm 2 Pressure pressing molding;

[0047] 3) After demoulding, dry at 100-150℃ for 3-8h to obtain a density of 1.9-2.5g / cm 3 Oxygen-producing column.

[0048] In a specific embodiment, the chlorate oxygen source can be one of potassium chlorate, sodium chlorate, potassium perchlorate or sodium perchlorate, or a mixture of any proportions thereof, and its particle size is preferably 30-80 mesh.

[0049] In a specific embodiment, the high thermal conductivity carbon-based nanomaterial can be any one of graphene, carbon nanotubes or nanographite, but graphene is most preferably used.

[0050] The present invention has no special requirements for the graphene used as a raw material, but further, the graphene can preferably be graphene with an oxygen content of less than 0.5%. More preferably, the graphene sheet size is 2-50 μm.

[0051] In a specific embodiment, the catalyst is preferably selected from one or a combination of nano-ferroferric oxide, nano-cobaltic oxide, nano-cobaltous oxide, nano-cobaltous oxide, nano-manganese dioxide or nano-nickel oxide, and the particle size of the nano-catalyst is 20-200 nm.

[0052] In a specific embodiment, the chlorine inhibitor is one of barium peroxide, sodium peroxide or lithium peroxide, or a combination of several of them in any proportion.

[0053] Unless otherwise specified, the amounts of raw material components and measurement parameters such as temperature and time involved in the embodiments of the present invention may have slight deviations within the range of weighing or measurement accuracy, and acceptable deviations caused by instrument testing accuracy or operating accuracy are allowed. Example

[0054] Example 1

[0055] 97 g of sodium chlorate and 0.3 g of graphene were weighed, mixed by ball milling and pre-treated by sieve vibration to obtain a powder with a particle size of less than 300 μm, which was used as a pre-treated oxygen source.

[0056] The obtained pretreated oxygen source and other raw material components, including 2.2 g of catalyst nano-cobalt tetroxide and 0.5 g of chlorine inhibitor barium peroxide, were placed in a twin-screw mixer and dry-mixed until uniformly mixed.

[0057] The mixed raw materials are poured into a custom mold and pressed on a tablet press at 10T / cm 2 The mold was pressed under pressure and dried in an oven at 120°C for 5 hours to obtain a density of 2.0 g / cm 3 Oxygen-producing column.

[0058] The oxygen-producing pellets prepared in this example were packaged into a solid oxygen generator and tested as follows:

[0059] 1) The solid oxygen generator was placed in an ultra-low temperature freezing chamber and frozen at -55°C for 48 hours. Combustion performance testing was then conducted at -55°C within the chamber, demonstrating that the oxygen-producing charge burned completely. Monitoring the combustion process using gas flow detection revealed a stable oxygen volume flow-time curve, with an oxygen production rate of 99%. The generated gas met the requirements for medical and aviation breathing oxygen (GB 8982-2009).

[0060] 2) During the combustion process, the wall temperature of the solid oxygen generator is 132°C. The reaction products after combustion are as follows: Figure 1 The morphology is layered accumulation, with no holes and no flow.

[0061] 3) The gas produced during the combustion of the solid oxygen generator was tested in accordance with the method specified in GB / T 11736-1989, "Standard Method for the Hygienic Examination of Chlorine in the Atmosphere of Residential Areas - Methyl Orange Spectrophotometric Method," and no chlorine was detected.

[0062] Example 2

[0063] 95.5 g of sodium chlorate and 0.5 g of graphene were weighed, mixed by ball milling and pre-treated by sieve vibration to obtain a powder with a particle size of less than 300 μm, which was used as a pre-treated oxygen source.

[0064] The obtained pretreated oxygen source and other raw material components, including 3.5 g of catalyst nano-cobalt trioxide and 0.5 g of chlorine inhibitor sodium peroxide, were placed in a twin-screw mixer and dry-mixed until uniformly mixed.

[0065] The mixed raw materials are poured into a custom mold and pressed on a tablet press at 10T / cm 2 The mold was pressed under pressure and dried in an oven at 130°C for 3 hours to obtain a density of 1.9 g / cm 3 Oxygen-producing column.

[0066] The oxygen-producing pellets prepared in this example were packaged into a solid oxygen generator and tested as follows:

[0067] 1) Place the solid oxygen generator in an ultra-low temperature freezing test chamber, freeze it at -55℃ for 48 hours, and then conduct a combustion performance test at -55℃ in the ultra-low temperature freezing test chamber. The oxygen-producing charge can burn completely; monitor the combustion process by using the gas flow detection method, such as Figure 2 As shown, the oxygen production volume flow-time curve is stable, and the oxygen production rate is 99.5%. The generated gas meets the requirements of medical and aviation breathing oxygen (GB 8982-2009).

[0068] 2) During the combustion process, the wall temperature of the solid oxygen generator is 128°C, and the reaction products after combustion are in the form of layered accumulation without any holes or flow.

[0069] 3) The gas produced during the combustion of the solid oxygen generator was tested in accordance with the method specified in GB / T 11736-1989, "Standard Method for the Hygienic Examination of Chlorine in the Atmosphere of Residential Areas - Methyl Orange Spectrophotometric Method," and no chlorine was detected.

[0070] Example 3

[0071] 96.5 g of sodium chlorate and 0.4 g of carbon nanotubes were weighed, mixed by ball milling and pre-treated by sieve vibration to obtain a powder with a particle size of less than 300 μm, which was used as a pre-treated oxygen source.

[0072] The obtained pretreated oxygen source and other raw material components, including 2.6 g of catalyst nano-cobaltous oxide and 0.5 g of chlorine inhibitor lithium peroxide, were placed in a twin-screw mixer and dry-mixed until uniformly mixed.

[0073] The mixed raw materials are poured into a custom mold and pressed on a tablet press at 10T / cm 2 The mold was pressed under pressure and dried in an oven at 110°C for 6 hours to obtain a density of 2.3 g / cm 3 Oxygen-producing column.

[0074] The oxygen-producing pellets prepared in this example were packaged into a solid oxygen generator and tested as follows:

[0075] 1) The solid oxygen generator was placed in an ultra-low temperature freezing chamber and frozen at -55°C for 48 hours. Combustion performance testing was then conducted at -55°C within the chamber, demonstrating that the oxygen-producing charge burned completely. Monitoring the combustion process using gas flow detection revealed a stable oxygen volume flow-time curve, with an oxygen production rate of 99.4%. The generated gas met the requirements for medical and aviation breathing oxygen (GB 8982-2009).

[0076] 2) During the combustion process, the wall temperature of the solid oxygen generator is 127°C, and the reaction products after combustion are in the form of layered accumulation without any holes or flow.

[0077] 3) The gas produced during the combustion of the solid oxygen generator was tested in accordance with the method specified in GB / T 11736-1989, "Standard Method for the Hygienic Examination of Chlorine in the Atmosphere of Residential Areas - Methyl Orange Spectrophotometric Method," and no chlorine was detected.

[0078] Comparative Example 1

[0079] 97.3 g of sodium chlorate was weighed, ball-milled, and sieved to obtain a powdered oxygen source with a particle size of less than 300 μm.

[0080] The obtained oxygen source and other raw material components, including 2.2 g of catalyst nano-cobalt tetroxide and 0.5 g of chlorine inhibitor barium peroxide, were placed in a twin-screw mixer and dry-mixed until uniformly mixed.

[0081] The mixed raw materials are poured into a custom mold and pressed on a tablet press at 10T / cm 2 The mold was pressed under pressure and dried in an oven at 120°C for 5 hours to obtain a density of 2.0 g / cm 3 Oxygen-producing column.

[0082] The oxygen-producing pellets were packaged into a solid oxygen generator and placed in an ultra-low temperature freezing test chamber. After being frozen at -40°C for 48 hours, an oxygen production test was conducted at -40°C in the ultra-low temperature freezing test chamber. The oxygen-producing pellets could burn smoothly with an oxygen production rate of 95%.

[0083] The packaged solid oxygen generator was then placed in an ultra-low temperature freezing test chamber. After being frozen at -55°C for 48 hours, an oxygen production test was conducted at -55°C in the ultra-low temperature freezing test chamber. The results showed that the oxygen-producing charge could not burn completely, and the oxygen production rate was only 31%.

[0084] Comparative Example 2

[0085] Weigh 97 g of sodium chlorate, 0.3 g of graphene, 2.2 g of nano-cobalt tetroxide, and 0.5 g of barium peroxide, place them together in a twin-screw mixer and dry mix them until they are uniformly mixed.

[0086] The mixed raw materials are poured into a custom mold and pressed on a tablet press at 10T / cm 2 The mold was pressed under pressure and dried in an oven at 120°C for 5 hours to obtain a density of 2.0 g / cm 3 Oxygen-producing column.

[0087] The oxygen-producing drug column is packaged into a solid oxygen generator, placed in an ultra-low temperature freezing test box, and frozen at -55℃ for 48 hours. Then, it is tested at -55℃ in the ultra-low temperature freezing test box and the performance is monitored by the gas flow detection method. Figure 3 As shown in the figure, the oxygen production volume flow-time curve is not smooth, the oxygen production column is not completely burned, and the oxygen production rate is 60.5%.

[0088] Comparative Example 3

[0089] Weigh 92 g of sodium chlorate, 0.5 g of potassium perchlorate, 2.5 g of nano-cobalt tetroxide, 2 g of iron powder, 1 g of titanium powder, 1 g of barium peroxide, and 1 g of kaolin, and dry-mix them together in a twin-screw mixer until they are uniformly mixed.

[0090] The mixed raw materials are poured into a custom mold and pressed on a tablet press at 10T / cm 2 The mold was pressed under pressure and dried in an oven at 120°C for 5 hours to obtain a density of 2.3 g / cm 3 Oxygen-producing column.

[0091] The oxygen-producing drug column was packaged into a solid oxygen generator, placed in an ultra-low temperature freezing test box, and frozen at -55°C for 48 hours. The test was then carried out in the ultra-low temperature freezing test box at -55°C.

[0092] The test results show that the oxygen-producing grain cannot burn stably at -55℃. During the combustion process, the wall temperature of the solid oxygen generator is too high, reaching 205℃. The oxygen-producing grain burns incompletely, and the oxygen production rate is only 72%. Figure 4 As shown, the residue after combustion appears hollow and flowing.

[0093] The technical features of the above embodiments of the present invention can be combined in any combination. To simplify the description, not all possible combinations of the technical features in the embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the description of the present invention.

[0094] The above embodiments represent several specific and detailed implementations of the present invention, but should not be construed as limiting the scope of protection of the present invention. It should be noted that persons of ordinary skill in the art may make various substitutions, modifications, or improvements without departing from the principles and purpose of the present invention, all of which are intended to be within the scope of protection of the present invention.

Claims

1. A low-temperature oxygen candle oxygen-generating charge, prepared from the following raw materials in percentage by weight: 95.5-98.5% of a pretreated oxygen source, 0.5-3.5% of a catalyst, and 0.2-1% of a chlorine inhibitor, wherein the pretreated oxygen source is a powdered oxygen source having a particle size of less than 300 μm obtained by doping a chlorate-based oxygen source with 0.2-0.65% by weight of a highly thermally conductive carbon-based nanomaterial.

2. The low-temperature oxygen candle oxygen generating column according to claim 1 is characterized in that The chlorate oxygen source in the pre-treatment oxygen source is one of potassium chlorate, sodium chlorate, potassium perchlorate or sodium perchlorate, or a mixture of any proportions of the above.

3. The low-temperature oxygen candle oxygen generating column according to claim 1 is characterized in that The high thermal conductivity carbon-based nanomaterial is any one of graphene, carbon nanotube or nanographite.

4. The low-temperature oxygen candle oxygen generating column according to claim 1 is characterized in that The catalyst is a nano-oxide catalyst of iron, cobalt, nickel or manganese.

5. The low-temperature oxygen candle oxygen generating column according to claim 4 is characterized in that The catalyst is selected from one of nano-ferroferric oxide, nano-cobaltic oxide, nano-cobaltic oxide, nano-cobaltous oxide, nano-cobaltous oxide, nano-manganese dioxide or nano-nickel oxide, or a combination thereof.

6. The low-temperature oxygen candle oxygen generating powder column according to claim 1, 4 or 5, characterized in that The particle size of the catalyst is 20-200 nm.

7. The low-temperature oxygen candle oxygen generating column according to claim 1 is characterized in that The chlorine inhibitor is one of barium peroxide, sodium peroxide or lithium peroxide, or a combination of several of them in any proportion.

8. The method for preparing the low-temperature oxygen candle oxygen-generating powder column according to claim 1, comprising: 1) adding the high thermal conductivity carbon-based nanomaterial in the proportion to the chlorate oxygen generating source, and ball milling the mixture to obtain a powdered pretreated oxygen generating source with a particle size of less than 300 μm; 2) dry-mixing the pretreated oxygen source, the catalyst, and the chlorine inhibitor in a mixer according to the mass percentage until uniformly mixed, and then pressing into a mold; 3) After demoulding, dry at 100-150℃ to obtain a density of 1.9-2.5g / cm 3 Oxygen-producing column.

9. The preparation method according to claim 8, wherein 10-15T / cm 2 The uniformly mixed raw materials are pressed into a mold under a pressure of 100 ℃.

10. The preparation method according to claim 8, characterized in that Drying time 3-8h.

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