Device and method for evaluating reaction activity of sulfur-containing tailing sand

Abstract

The invention discloses a device for evaluating the reaction activity of sulfur-containing tailing sand, which comprises a reaction container, a heater, a humidifier and a control and data acquisition system, the reaction container is provided with a gas inlet and a gas outlet and is used for outputting and feeding composite gas of oxygen and nitrogen into the reaction container, and a tray for placing a sulfur-containing tailing sand sample is arranged in the reaction container. The heater is used for controlling the temperature in the reaction container, the humidifier is used for controlling the humidity in the reaction container, and the reaction container is provided with an oxygen sensor, a humidity sensor and a temperature sensor which are used for dynamically collecting the oxygen content, the temperature and the humidity in the reaction container respectively; and the heater, the humidifier, the oxygen sensor, the humidity sensor and the temperature sensor are respectively connected with the control and data acquisition system. The invention further discloses a method for evaluating the reaction activity of the sulfur-containing tailing sand, the reaction activity of the sulfur-containing tailing sand can be evaluated by measuring the oxygen consumption of the sulfur-containing tailing sand by adopting the device, the test is convenient, and the method can be suitable for environments with different temperatures and humidity.

Description

Technical Field

[0001] The invention belongs to the technical field of material reactivity detection, and in particular relates to a device and method for evaluating the reactivity of sulfur-containing tailings sand. Background Art

[0002] The tailings produced by non-ferrous metal mines contain a lot of sulfides, especially pyrite and associated pyrite, which are the main sulfur sources in China, accounting for 83.4% of China's total sulfur resources. There are nearly 900 pyrite mines, with an annual output of 13.2 million tons of pyrite, which produces a large amount of sulfur-containing tailings. During the accumulation and storage of these sulfur-containing tailings on the surface, the sulfide minerals will react with air and water under external oxidation conditions to generate sulfates and produce a large amount of hydrogen ions, forming an acidic environment, further eroding the tailings dam, and easily causing dam failure accidents.

[0003] The best way to recycle sulfur-containing tailings sand is to use tailings cementation filling technology, using sulfur-containing tailings sand as aggregate to prepare a filling body and fill it into the mine goaf. However, the types of sulfides, sulfur forms and their contents in different tailings vary greatly. In addition, due to different stacking times, the degree of oxidation is also different, which makes it impossible to accurately evaluate the reactivity of sulfur-containing tailings, which brings great difficulties to the filling and utilization of sulfur-containing tailings. At present, the determination of sulfur content in tailings is mostly expressed as a percentage of sulfur element, but high sulfur content cannot accurately reflect the reactivity of sulfur-containing tailings. Therefore, how to evaluate the reactivity of sulfur-containing tailings sand is lacking in current research. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a device and method for evaluating the reactivity of sulfur-containing tailings sand. The device and method can evaluate the reactivity of sulfur-containing tailings sand by measuring the oxygen consumption of sulfur-containing tailings sand under different temperature and humidity environments. It has the advantage of convenient testing and makes up for the current shortcomings in the evaluation of the reactivity of sulfur-containing tailings sand.

[0005] The present invention is achieved through the following technical solutions.

[0006] The invention provides a device for evaluating the reactivity of sulfur-containing tailings sand, comprising a reaction container, a heater, a humidifier, and a control and data acquisition system. The reaction container is provided with an air inlet and an air outlet for inputting and outputting a composite gas of oxygen and nitrogen into and out of the reaction container, and a tray for placing a sulfur-containing tailings sand sample is provided inside the reaction container. The heater is used to control the temperature in the reaction container, and the humidifier is used to control the humidity in the reaction container. The reaction container is equipped with an oxygen sensor, a humidity sensor, and a temperature sensor for dynamically collecting the oxygen content, humidity, and temperature in the reaction container respectively. The heater, the humidifier, the oxygen sensor, the humidity sensor, and the temperature sensor are respectively connected to the control and data acquisition system.

[0007] Furthermore, a heat conducting plate with evenly distributed circular holes is arranged at the bottom of the reaction container, the tray is located above the heat conducting plate, and the heater is located below the heat conducting plate.

[0008] Furthermore, a humidification channel is extended outward from the side wall of the reaction container, the humidifier is located outside the reaction container and the humidifier outlet is connected to the humidification channel to introduce moisture into the reaction container.

[0009] Furthermore, the air inlet is connected to an air inlet pipe, the air inlet pipe is provided with an air inlet valve, and the air outlet is connected to an air outlet pipe, the air outlet pipe is provided with an air outlet valve.

[0010] Furthermore, the reaction container is a rectangular parallelepiped, the air inlet and the air outlet are respectively located on both sides of the reaction container, and the oxygen sensor, the humidity sensor, and the temperature sensor are arranged on the same side of the reaction container and distributed on the opposite side of the humidification channel.

[0011] The present invention also provides a test method using the above device, comprising the following steps:

[0012] Step 1: evenly spread the sulfur-containing tailings sand sample on a tray, and then place the tray on a heat-conducting plate in a reaction vessel;

[0013] Step 2: Turn on the control and data acquisition system and check whether the oxygen sensor, temperature sensor, and humidity sensor are working properly;

[0014] Step 3: Set a predetermined temperature and humidity, and control the heater and humidifier switches by the control and data acquisition system to ensure that the temperature and humidity inside the reaction container stably reach the predetermined temperature and humidity;

[0015] Step 4: Deliver a composite gas of oxygen and nitrogen with a set oxygen concentration into the reaction container through the air inlet. After the oxygen content in the reaction container stabilizes, close the air inlet valve and the air outlet valve of the reaction container and record the oxygen content at this moment. 0 ; Nitrogen is an inert gas and does not participate in the reaction. When mixed with oxygen, it can form gases with different oxygen concentrations;

[0016] Step 5: After the reaction lasts for 1 hour, the oxygen content O in the reaction vessel is recorded by the oxygen sensor. 1 ;

[0017] Step 6: Repeat step 4 and step 5 for 4 times in total, and record the oxygen content O in the reaction container after 1 hour of reaction by the control and data acquisition system. 2 , O 3 , O 4 and O 5 ;

[0018] Step 7: Calculate the oxygen concentration change rate V of sulfur-containing tailings per unit time based on the obtained data n, the formula is as follows:

[0019] V n =(O 0 -O n ) / t

[0020] Wherein, t is the reaction time, which is 1h; n is the oxygen concentration during the nth reaction, where n ranges from 1 to 5;

[0021] Step 8: The oxygen concentration change rate V calculated in step 7 is 1 、V 2 、V 3 、V 4 and V 5 Taking oxygen concentration change rate of sulfur-containing tailings sand as the ordinate and time as the abscissa, a curve of oxygen concentration change rate of sulfur-containing tailings sand against time is plotted to quantitatively evaluate the reaction activity of sulfur-containing tailings sand.

[0022] The beneficial effects of the present invention are:

[0023] The device and method of the present invention can evaluate the reaction activity of sulfur-containing tailings sand by measuring the oxygen consumption under different temperature and humidity environments, and the test is convenient, which makes up for the current shortcomings in the evaluation of the reaction activity of sulfur-containing tailings sand. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the device proposed by the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the reaction container in the device proposed by the present invention.

[0026] Figure 3 This is a schematic diagram of the structure of the heater in the device proposed by the present invention.

[0027] Figure 4 This is the oxygen concentration change rate-time curve of the sulfur-containing tailings sand in Example 2-3.

[0028] In the figure: reaction container 1, air inlet 11, air outlet 12, tray 13, heat conducting plate 14, hole 141, humidification channel 15, heater 2, humidifier 3, control and data acquisition system 4, oxygen sensor 5, humidity sensor 6, temperature sensor 7, air inlet pipe 111, air inlet valve 112, air outlet pipe 121, air outlet valve 122. DETAILED DESCRIPTION

[0029] The following further describes the structures involved in the present invention or the technical terms used in these descriptions. These descriptions are only used as examples to illustrate how the methods of the present invention are implemented, and cannot constitute any limitation to the present invention.

[0030] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left" and "right" indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the positions or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present invention, unless otherwise clearly specified and limited, "connection", "fixation" and the like should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Example 1

[0033] like Figure 1-3 As shown, a device for evaluating the reactivity of sulfur-containing tailings includes a reaction vessel 1, a heater 2, a humidifier 3, and a control and data acquisition system 4. The reaction vessel 1 is provided with an air inlet 11 and an air outlet 12 for inputting and outputting a composite gas of oxygen and nitrogen into and out of the reaction vessel 1. A tray 13 for placing a sulfur-containing tailings sample is provided inside the reaction vessel. The heater 2 is used to control the temperature in the reaction vessel 1. The humidifier 3 is used to control the humidity in the reaction vessel 1. The reaction vessel 1 is equipped with an oxygen sensor 5, a humidity sensor 6, and a temperature sensor 7 for dynamically collecting the oxygen content, humidity, and temperature in the reaction vessel 1. The heater 2, the humidifier 3, the oxygen sensor 5, the humidity sensor 6, and the temperature sensor 7 are connected to the control and data acquisition system 4, respectively.

[0034] As an optional embodiment, Figure 2 As shown, a heat conducting plate 14 with circular holes 141 evenly distributed is arranged at the bottom of the reaction container 1, the tray 13 is located above the heat conducting plate 14, and the heater 2 is located below the heat conducting plate 14. The heat conducting plate 14 is made of a material with heat conductivity, such as a steel plate. The circular holes 141 are for facilitating internal air circulation and heat transfer. The heater 2 can be a tubular heater, and the entire tubular structure can be bent into different forms to adapt to the heat distribution required for the space or surface to be heated. The heater 2 is connected to the control and data acquisition system 4, and its switch and temperature rise are controlled by the control and data acquisition system 4.

[0035] As an optional embodiment, a humidification channel 15 is extended outward from the side wall of the reaction container 1, and the humidifier 3 is located outside the reaction container 1 and the humidifier outlet is connected to the humidification channel 15 to introduce moisture into the reaction container 1. The humidifier 3 is connected to the control and data acquisition system 4, and its switch is controlled by the control and data acquisition system 4.

[0036] As an optional embodiment, Figure 1 As shown, the air inlet 11 is connected to an air inlet pipe 111, which is provided with an air inlet valve 112, and the air outlet 12 is connected to an air outlet pipe 121, which is provided with an air outlet valve 122. The air inlet valve 112 and the air outlet valve 122 control the on-off and flow rate of the air inlet and the air outlet, respectively.

[0037] As an optional embodiment, Figure 2 As shown, the reaction container 1 is a rectangular parallelepiped, the air inlet 11 and the air outlet 12 are respectively located on both sides of the reaction container 1, and the oxygen sensor 5, the humidity sensor 6, and the temperature sensor 7 are arranged on the same side of the reaction container 1 and distributed on the opposite side of the humidification channel 15.

[0038] The oxygen sensor 5 is connected to the control and data acquisition system 4, and transmits the oxygen content data in the reaction container 1 to the control and data acquisition system 4 in real time. The temperature sensor 6 is connected to the control and data acquisition system 4, and transmits the temperature data in the reaction container 1 to the control and data acquisition system 4 in real time. The humidity sensor 7 is connected to the control and data acquisition system 4, and transmits the humidity data in the reaction container 1 to the control and data acquisition system 4 in real time.

[0039] Example 2

[0040] This embodiment is a test method performed using the device described in Example 1, comprising the following steps:

[0041] Step 1: In this embodiment, sulfur-containing tailings in Nanjing are selected, and the sulfur-containing tailings sand sample A is evenly spread on a tray, and then the tray is placed on a steel plate in a reaction vessel 1;

[0042] Step 2: Open the control and data acquisition system 4 and check whether the oxygen sensor 5, the temperature sensor 6 and the humidity sensor 7 are working properly;

[0043] Step 3: Set the temperature to 30°C and the humidity to 50%, and control the heater 2 and the humidifier 3 by the control and data acquisition system 4 to make the interior of the reaction container 1 stably reach the predetermined temperature and humidity;

[0044] Step 4: Select the oxygen concentration of 50% to conduct the test. A composite gas of 50% oxygen and 50% nitrogen is delivered into the reaction vessel 1 through the air inlet. After the oxygen content in the reaction vessel 1 is stable, the air inlet valve 112 and the air outlet valve 122 of the reaction vessel 1 are closed. The oxygen content at this moment is recorded as O 0 =50%;

[0045] Step 5: After the reaction lasts for 1 hour, the oxygen content O in the reaction container 1 is recorded by the oxygen sensor 5. 1 =28%;

[0046] Step 6: Repeat step 4 and step 5 for 4 times in total, and record the oxygen content O in the reaction container 1 after each reaction for 1 hour through the control and data acquisition system 4. 2 =34%, O 3 =37%, O 4 =39%, O 5 =40%;

[0047] Step 7: Based on the obtained data and formula V n =(O 0 -O n ) / tCalculate the oxygen concentration change rate V of sulfur-containing tailings per unit time n , we get V 1 =(O 0 -O 1 ) / t=22% / h,V 2 =(O 0 -O 2 ) / t=16% / h,V 3 =(O 0 -O 3 ) / t=13% / h,V 4 =(O 0 -O 4 ) / t=11% / h,V 5 =(O 0 -O 5 ) / t=10% / h;

[0048] Step 8: The oxygen concentration change rate V calculated in step 7 is 1 、V 2 、V 3 、V 4 and V 5 As the ordinate, time as the abscissa, draw the oxygen concentration change rate-time curve of sulfur-containing tailings sand, such as Figure 4 shown.

[0049] Example 3

[0050] This embodiment is a test method performed using the device described in Example 1, and is different from Example 2 in that the source of the sulfur-containing tailings sand sample is different.

[0051] The test method includes the following steps:

[0052] Step 1: In this embodiment, sulfur-containing tailings from a certain place in Maanshan are selected, and the sulfur-containing tailings sand sample B is evenly spread on a tray, and then the tray is placed on a steel plate in a reaction vessel 1;

[0053] Step 2: Open the control and data acquisition system 4 and check whether the oxygen sensor 5, the temperature sensor 6 and the humidity sensor 7 are working properly;

[0054] Step 3: Set the temperature to 30°C and the humidity to 50%, and control the heater 2 and the humidifier 3 by the control and data acquisition system 4 to make the interior of the reaction container 1 stably reach the predetermined temperature and humidity;

[0055] Step 4: Select the oxygen concentration of 50% to conduct the test. A composite gas of 50% oxygen and 50% nitrogen is delivered into the reaction vessel 1 through the air inlet. After the oxygen content in the reaction vessel 1 is stable, the air inlet valve 112 and the air outlet valve 122 of the reaction vessel are closed. The oxygen content at this moment is recorded as O 0 =50%;

[0056] Step 5: After the reaction lasts for 1 hour, the oxygen content O in the reaction container 1 is recorded by the oxygen sensor 5. 1 =37%;

[0057] Step 6: Repeat step 4 and step 5 for 4 times in total, and record the oxygen content O in the reaction container 1 after each reaction for 1 hour through the control and data acquisition system 4. 2 =39%, O 3 =41%, O 4 =42%, O 5 =43%;

[0058] Step 7: Based on the obtained data and formula V n =(O 0 -O n ) / tCalculate the oxygen concentration change rate V of sulfur-containing tailings per unit time n , we get V 1 =(O 0 -O 1 ) / t=13% / h,V 2 =(O 0 -O 2 ) / t=11% / h,V 3 =(O 0 -O 3 ) / t=9% / h,V4 =(O 0 -O 4 ) / t=8% / h,V 5 =(O 0 -O 5 ) / t=7% / h;

[0059] Step 8: The oxygen concentration change rate V calculated in step 7 is 1 、V 2 、V 3 、V 4 and V 5 As the ordinate, time as the abscissa, draw the oxygen concentration change rate-time curve of sulfur-containing tailings sand, such as Figure 4 shown.

[0060] The active sulfides in the tailings will participate in the oxidation reaction and consume oxygen. The greater the reaction activity, the more oxygen is consumed per unit time, and the faster the rate of change of oxygen concentration. If there is no sulfur tailings, the oxygen concentration will remain unchanged. Therefore, Figure 4 It can be seen that the rate of change of oxygen concentration of sample A is higher than that of sample B, so the reactivity of A is higher. The rate of change of oxygen concentration in the first hour can also be used to characterize the reactivity of sulfur-containing tailings.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for evaluating the reactivity of sulfur-containing tailings sand, characterized in that: It includes a reaction container, a heater, a humidifier, a control and data acquisition system. The reaction container is provided with an air inlet and an air outlet for inputting and outputting a composite gas of oxygen and nitrogen into and out of the reaction container. A tray for placing sulfur-containing tailings sand samples is provided inside. The heater is used to adjust the temperature in the reaction container. The humidifier is used to adjust the humidity in the reaction container. The reaction container is installed with an oxygen sensor, a humidity sensor, and a temperature sensor for dynamically collecting the oxygen content, humidity, and temperature in the reaction container. The heater, the humidifier, the oxygen sensor, the humidity sensor, and the temperature sensor are respectively connected to the control and data acquisition system.

2. A device for evaluating the reactivity of sulfur-containing tailings sand according to claim 1, characterized in that: A heat conducting plate with evenly distributed circular holes is arranged at the bottom of the reaction container, the tray is located above the heat conducting plate, and the heater is located below the heat conducting plate.

3. A device for evaluating the reactivity of sulfur-containing tailings sand according to claim 1, characterized in that: The side wall of the reaction container is connected to the outside with a humidification channel, the humidifier is located outside the reaction container and the humidifier outlet is connected to the humidification channel.

4. The device for evaluating the reactivity of sulfur-containing tailings sand according to claim 1, characterized in that: The air inlet is connected to an air inlet pipeline, the air inlet pipeline is provided with an air inlet valve, and the air outlet is connected to an air outlet pipeline, the air outlet pipeline is provided with an air outlet valve.

5. The device for evaluating the reactivity of sulfur-containing tailings sand according to claim 3, characterized in that: The reaction container is a rectangular parallelepiped, with an air inlet and an air outlet respectively located on both sides of the reaction container. The oxygen sensor, the humidity sensor and the temperature sensor are arranged on the same side of the reaction container and distributed on the opposite side of the humidification channel.

6. The test method according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: evenly spread the sulfur-containing tailings sand sample on a tray, and then place the tray on a heat-conducting plate in a reaction vessel; Step 2: Turn on the control and data acquisition system and check whether the oxygen sensor, temperature sensor, and humidity sensor are working properly; Step 3: Set a predetermined temperature and humidity, and control the heater and humidifier switches by the control and data acquisition system to ensure that the temperature and humidity inside the reaction container stably reach the predetermined temperature and humidity; Step 4: transport a composite gas of oxygen and nitrogen with a set oxygen concentration into the reaction container through the air inlet. After the oxygen content in the reaction container is stable, close the air inlet valve and the air outlet valve of the reaction container, and record the oxygen content O0 at this moment; Step 5: After the reaction lasts for 1 hour, the oxygen content O1 in the reaction container is recorded by an oxygen sensor; Step 6, repeat step 4 and step 5 for 4 times in total, and record the oxygen contents O2, O3, O4 and O5 in the reaction container after 1 hour of reaction respectively through the control and data acquisition system; Step 7: Calculate the oxygen concentration change rate V of sulfur-containing tailings per unit time based on the obtained data n , the formula is as follows: V n =(O0-O n ) / t Wherein, t is the reaction time, which is 1h; n is the oxygen concentration during the nth reaction, where n ranges from 1 to 5; Step 8. Use the oxygen concentration change rates V1, V2, V3, V4 and V5 calculated in step 7 as the ordinate and time as the abscissa to draw the oxygen concentration change rate-time curve of the sulfur-containing tailings sand for quantitatively evaluating the reaction activity of the sulfur-containing tailings sand.

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