Method for reducing soot blowing time in lead assaying method

Abstract

The invention belongs to the technical field of metal detection and analysis, and particularly relates to a method for reducing soot blowing time in a lead assaying method, which comprises the following steps: paving sodium carbonate at the bottom of a clay crucible, weighing a sample and putting the sample into the clay crucible; adding a soot blowing protective agent, a reducing agent, lead oxide, borax, quartz sand and a covering agent into the clay crucible; placing the clay crucible in a muffle furnace for smelting; casting the melt in the clay crucible into a dry iron mold, cooling, and discarding upper-layer slag to obtain an alloy block of lead and precious metal; putting the alloy block into a magnesia cupel; the magnesia cupel and an oxygen slow-release block are put into a hearth of a muffle furnace, a furnace door is closed, the ash blowing process is executed, and the oxygen slow-release block is formed by evenly mixing solid lithium perchlorate and a binder and then pressing the mixture. According to the method, the soot blowing time of a lead assaying analysis method is shortened, the mass loss of the precious metal under long-time soot blowing is reduced, the precious metal analysis process is accelerated, and the accuracy and reliability of an analysis result are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal detection and analysis, and in particular relates to a method for reducing the ash blowing time in a lead assay method, which can be used to speed up analysis efficiency and improve the accuracy and reliability of analysis results. Background Art

[0002] The statements in this section are merely intended to provide background information related to the technical solution of the present application to aid understanding, and they do not necessarily constitute prior art for the technical solution of the present application.

[0003] Precious metals play a very important role in modern industry, but the content of precious metals in ores is usually low. Trace and trace amounts of precious metals bring difficulties to the analysis and determination process, and the analysis results lack accuracy and reliability. The lead assay is a classic method for detecting precious metal elements in enriched ores. It is a method of applying metallurgical principles to analytical chemistry and one of the main means of modern precious metal analysis. The lead assay is a more accurate and reliable analysis method for determining trace and trace precious metal elements in ores. The lead assay is to mix the ore or smelting product with a collector, a reducing agent, and a solid flux, heat and melt it in a clay crucible to make slag, and finally pour the molten precious metal into a dry iron mold to cool it. The precious metal has a large density and settles at the bottom of the mold, and the slag floats on the upper layer. After the melt is cooled, it is poured out of the iron mold, and the upper slag is discarded to obtain a lead buckle with a mass of about 30-40g. The elements contained in the lead buckle are lead, gold, palladium and platinum. In this process, the added lead oxide can be used as a precious metal collector to efficiently enrich precious metals (10 5 times or more), can enrich the precious metals in the sample into dozens of grams of lead buckles, remove the lead in the lead buckles through the ash blowing process, and obtain dozens of milligrams of precious metal alloy particles, and the composition of the precious metal alloy particles is simple, which is convenient for subsequent analysis and determination. The lead assay method plays the role of decomposing samples and enriching precious metals, and is mainly divided into several important steps: batching, smelting and ash blowing. However, in the process of ash blowing oxidation and lead removal, it is necessary to slightly open the muffle furnace door to allow air to enter the furnace cavity, increase the oxygen concentration in the furnace cavity, and accelerate the volatilization of lead. In this step, the oxygen concentration is low and the ash blowing time is long, resulting in serious loss of gold and silver during the ash blowing process, affecting the accuracy of the analysis results, and the analysis efficiency is not high, and the analysis cycle of a single sample is long. Summary of the invention

[0004] The present invention proposes a method for reducing the ash blowing time in the lead gold assay by studying the factors that affect the ash blowing time of the lead gold assay, thereby solving the problems of low oxygen concentration and long ash blowing time in the ash blowing process of the lead gold assay. The method can effectively reduce the ash blowing time of the lead gold assay, improve the analysis efficiency, and also improve the accuracy and reliability of the analysis results.

[0005] One aspect of the present invention relates to a method for reducing the ash blowing time in the lead assay method, which comprises: spreading sodium carbonate on the bottom of a clay crucible, weighing a sample and putting it into the clay crucible; adding an ash blowing protective agent, a reducing agent, lead oxide, borax and quartz sand into the clay crucible; adding a covering agent into the clay crucible; placing the clay crucible in a muffle furnace, smelting at a temperature of 940-980° C. for a period of time, then heating to 1140-1180° C. and smelting for a period of time; placing the clay crucible in a muffle furnace, and then heating the clay crucible to 1140-1180° C. for a period of time; The melt in the earthen crucible is cast into a dry iron mold, and the upper slag is discarded after cooling to obtain an alloy block of lead and precious metals; the magnesia ash dish is preheated at 940-980°C for more than 20 minutes to remove organic matter and gas in the magnesia ash dish, and then the alloy block is placed in the magnesia ash dish; the magnesia ash dish and the oxygen slow-release block are placed in the muffle furnace, the furnace door is closed, and an ash blowing process is performed, wherein the oxygen slow-release block is formed by evenly mixing solid lithium perchlorate and a binder and then pressing them.

[0006] In one embodiment, the oxygen slow-release block decomposes layer by layer in the muffle furnace and slowly releases oxygen.

[0007] In one embodiment, the dust blowing protection agent includes a silver nitrate solution.

[0008] In one embodiment, the reducing agent is one or more of flour, starch, and coke.

[0009] In one embodiment, the ash blowing protective agent, reducing agent, lead oxide, borax and quartz sand are sequentially added into a clay crucible.

[0010] In one embodiment, the clay crucible is placed in a muffle furnace and smelted at 960° C. for 0.5 h, then heated to 1160° C. and smelted for 0.5 h.

[0011] In one embodiment, preheating the magnesia ash pan at 940-980° C. for more than 20 min includes preheating the magnesia ash pan at 960° C. for 30 min.

[0012] In one embodiment, during the ash blowing process, the lead in the alloy block is oxidized to lead oxide and absorbed by the pores of the magnesia ash pan, and the precious metal alloy particles remain in the magnesia ash pan. The method further includes: analyzing and measuring the precious metal alloy particles.

[0013] In one embodiment, the method further comprises: after obtaining the alloy block of lead and precious metal, hammering the alloy block into a cube.

[0014] Beneficial effects: The present invention solves the problems of low oxygen concentration and long ash blowing time during the ash blowing process of lead assay, which can effectively reduce the ash blowing time of lead assay and improve the analysis efficiency. At the same time, it reduces the loss of precious metals during the ash blowing process and can improve the accuracy and reliability of the analysis results. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The embodiments of the present invention are further described below with reference to the accompanying drawings, in which:

[0016] Figure 1 A flow chart of a method for reducing dust blowing time in lead assay according to one embodiment is shown. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail by specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] Figure 1 A flow chart of a method for reducing the ash blowing time in lead assay according to an embodiment is shown, which comprises the following steps:

[0019] Step 101: Spread sodium carbonate on the bottom of a clay crucible, and weigh a sample and put it into the clay crucible.

[0020] Step 102: Add ash blowing protective agent, reducing agent, lead oxide, borax and quartz sand into the clay crucible.

[0021] Lead oxide is used as a trapping agent in the lead assay, which can effectively capture precious metal elements such as gold and silver from the sample into the lead buckle, ensuring the recovery of precious metal elements and the accuracy of analysis. The function of the ash blowing protective agent is to reduce the loss of trace precious metal elements to be measured during the ash blowing stage and improve the accuracy of the analysis. The melting point of borax is relatively low. After adding it, it can effectively lower the melting point of the slag, making the melting process easier. Quartz sand is mainly used as an impurity remover and flux here. Specifically, quartz sand can react with impurities at high temperatures to generate compounds such as ferrosilicates. These compounds precipitate in the melt, thereby reducing the impurity content in the melt. At the same time, quartz sand can also promote the penetration and melting of lead, lower the melting point of lead, and improve smelting efficiency.

[0022] Step 103: Add a covering agent to the clay crucible.

[0023] The main function of the covering agent is to cover the molten metal surface to prevent the molten metal from directly contacting oxygen in the air, thereby reducing the oxidation loss of the metal. The covering agent can be, for example, sodium chloride or a mixture of borax and sodium carbonate.

[0024] Step 104: Place the clay crucible in a muffle furnace, smelt it at 940-980° C. for a period of time, then heat it to 1140-1180° C. and smelt it for a period of time.

[0025] Step 105: Cast the molten material in the clay crucible into a dry iron mold, discard the upper slag after cooling, and obtain an alloy block of lead and precious metals (also called a lead buckle).

[0026] Step 106: preheat the magnesia ash dish at 940-980° C. for more than 20 minutes to remove organic matter and gas in the magnesia ash dish, and then place the alloy block into the magnesia ash dish.

[0027] Step 107: Place the magnesia ash dish and the oxygen slow-release block into the muffle furnace, close the furnace door, and perform the ash blowing process. The oxygen slow-release block is formed by pressing after evenly mixing solid lithium perchlorate and a binder.

[0028] Lithium perchlorate usually exists in solid form, and begins to melt into liquid at around 240°C. When the thermal decomposition temperature reaches 507°C, it can undergo a decomposition reaction and release oxygen. Since the oxygen slow-release block is formed by pressing solid lithium perchlorate and a binder after being evenly mixed, the oxygen slow-release block will decompose layer by layer and slowly release oxygen at high temperatures. The oxygen slow-release block gradually melts from the outer layer under the high temperature of the ash blowing, exposing the lithium perchlorate solid on the surface, which will decompose and produce oxygen when heated. Since the melting process of the oxygen slow-release block starts from the edge and gradually moves inward, the lithium perchlorate is also exposed layer by layer, achieving the purpose of slowly and gradually releasing oxygen, and avoiding the problem of excessive oxygen release from the simultaneous thermal decomposition of a large amount of lithium perchlorate.

[0029] The chemical reaction equation involved in the oxygen release process of the oxygen slow-release block is as follows;

[0030] LiClO4(s)→LiClO4(l)

[0031] LiClO4(l)→LiCl(l)+2O2(g)

[0032] LiClO4(l)→LiCl(s)+2O2(g)

[0033] In one embodiment, the dust blowing protection agent includes a silver nitrate solution.

[0034] In one embodiment, the reducing agent may be one or more of flour, starch, and coke.

[0035] In one embodiment, the step 105 further comprises hammering the obtained alloy block of lead and precious metal into a cube.

[0036] Example 1

[0037] A method for reducing the blowing time of lead assay ash comprises the following steps:

[0038] 1. Spread 40g of sodium carbonate on the bottom of a clay crucible, weigh 2g of a high-grade sample and put it into the crucible, add a silver nitrate solution (e.g., a concentration of 1000g / L) as a ash blowing protective agent, 3g of flour, 150g of lead oxide, 10g of borax, 13g of quartz sand, and then add 10g of a covering agent;

[0039] 2. Place the above ingredients and clay crucible in a muffle furnace, smelt at 960°C for 0.5h, then heat to 1160°C, and take out of the furnace after 0.5h. The total smelting time is 1h;

[0040] 3. Pour the melt in the clay crucible into a dry iron mold, discard the upper slag after cooling, and obtain a lead buckle with a mass of 35g. Hammer the lead buckle into a cube;

[0041] 4. After preheating the magnesia ash dish at 960℃ for 30 minutes, put the obtained lead button into the ash dish, then place the "sustained-release capsule" in the furnace, close the furnace door, and wait until the lead is completely oxidized to lead oxide and absorbed by the pores of the ash dish. The ash blowing is completed when there are only precious metal alloy particles in the ash dish. The whole ash blowing time is 30 minutes, which saves 20 minutes compared with the traditional lead assay ash blowing time of 50 minutes.

[0042] Example 2

[0043] A method for reducing the blowing time of lead assay ash comprises the following steps:

[0044] 1. Spread 40g of sodium carbonate on the bottom of a clay crucible, weigh 10g of a low-grade sample and put it into the crucible, add a silver nitrate solution (e.g., a concentration of 1000g / L) as a ash blowing protective agent, 3g of flour, 150g of lead oxide, 10g of borax, 13g of quartz sand, and then add 10g of a covering agent;

[0045] 2. Place the above ingredients and clay crucible in a muffle furnace, smelt at 960°C for 0.5h, then heat to 1160°C, and take out of the furnace after 0.5h. The total smelting time is 1h;

[0046] 3. Pour the molten material in the clay crucible into a dry iron mold, discard the upper slag after cooling, and obtain a lead buckle with a mass of 38g. Hammer the lead buckle into a cube;

[0047] 4. After preheating the magnesia ash dish at 960℃ for 30 minutes, put the obtained lead button into the ash dish, then place the "sustained-release capsule" in the furnace, close the furnace door, and wait until the lead is completely oxidized to lead oxide and absorbed by the pores of the ash dish. The ash blowing is completed when there are only precious metal alloy particles in the ash dish. The whole ash blowing time is 32 minutes, which saves 18 minutes compared with the traditional lead assay ash blowing time of 50 minutes.

[0048] References herein to "various embodiments", "some embodiments", "one embodiment" or "an embodiment" etc. refer to that a particular feature, structure or property described in conjunction with the embodiment is included in at least one embodiment. Therefore, the phrases "in various embodiments", "in some embodiments", "in one embodiment" or "in an embodiment" etc. appearing throughout this document do not necessarily refer to the same embodiment. In addition, particular features, structures or properties may be combined in any suitable manner in one or more embodiments. Therefore, the particular features, structures or properties shown or described in conjunction with one embodiment may be combined in whole or in part with features, structures or properties of one or more other embodiments without restriction, as long as the combination is not illogical or inoperable. Expressions similar to "according to A", "based on A", "through A" or "using A" appearing herein are intended to be non-exclusive, that is, "according to A" may cover "according to A only" or "according to A and B", unless it is specifically stated that its meaning is "according to A only". In this application, for the sake of clarity, some exemplary operating steps are described in a certain order, but those skilled in the art will understand that each of these operating steps is not essential, and some of the steps may be omitted or replaced by other steps. These operation steps do not have to be executed sequentially in the manner shown; on the contrary, some of these operation steps can be executed in different orders or in parallel according to actual needs, as long as the new execution manner is not illogical or inoperable.

[0049] Some exemplary embodiments of the present invention are described above. It can be understood that the above embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention. The features in these embodiments can be recombined in a suitable manner, and the scheme obtained thereby is still within the protection scope required by the present invention. Based on the above embodiments, all other embodiments obtained by those skilled in the art without making creative work, that is, all modifications, equivalent substitutions and improvements made within the spirit and principles of this application, fall within the protection scope required by the present invention.

Claims

1. A method for reducing the ash blowing time in lead assay, characterized in that: include: Place sodium carbonate on the bottom of a clay crucible and weigh a sample into the clay crucible; Add ash blowing protective agent, reducing agent, lead oxide, borax and quartz sand into a clay crucible; Adding covering agent to clay crucible; Place the clay crucible in a muffle furnace, smelt it at 940-980°C for a period of time, then heat it to 1140-1180°C and smelt it for a period of time; The molten material in the clay crucible is cast into a dry iron mold, and after cooling, the upper slag is discarded to obtain an alloy block of lead and precious metals; Preheating the magnesia ash dish at 940-980° C. for more than 20 minutes to remove organic matter and gas in the magnesia ash dish, and then placing the alloy block in the magnesia ash dish; The magnesia ash dish and the oxygen slow-release block are placed in the furnace of the muffle furnace, the furnace door is closed, and the ash blowing process is performed, wherein the oxygen slow-release block is formed by pressing after solid lithium perchlorate and a binder are uniformly mixed.

2. The method for reducing the ash blowing time in the lead assay method according to claim 1, wherein: The oxygen slow-release block is decomposed layer by layer in the muffle furnace and slowly releases oxygen.

3. The method for reducing the ash blowing time in the lead assay method according to claim 1, wherein: The dust blowing protective agent includes a silver nitrate solution.

4. The method for reducing the ash blowing time in the lead assay method according to claim 1, wherein: The reducing agent is one or more of flour, starch and coke.

5. The method for reducing the ash blowing time in the lead assay method according to claim 4, wherein: The ash blowing protective agent, reducing agent, lead oxide, borax and quartz sand are sequentially added into a clay crucible.

6. The method for reducing the ash blowing time in the lead assay method according to claim 1, wherein: After placing the clay crucible in a muffle furnace, it was smelted at 960°C for 0.5 h, and then heated to 1160°C and smelted for 0.5 h.

7. The method for reducing the ash blowing time in the lead assay method according to claim 1, wherein: The preheating of the magnesia ash dish at 940-980° C. for more than 20 minutes includes preheating the magnesia ash dish at 960° C. for 30 minutes.

8. The method for reducing the ash blowing time in the lead assay method according to claim 1, wherein: During the ash blowing process, the lead in the alloy block is oxidized to lead oxide and absorbed by the pores of the magnesia ash dish, and the precious metal alloy particles remain in the magnesia ash dish. The method also includes: analyzing and measuring the precious metal alloy particles.

9. The method for reducing the dust blowing time in the lead assay method according to claim 1, further comprising: After obtaining the alloy block of lead and precious metal, the alloy block is hammered into a cube.

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