CN114371271A - Heavy metal soil detection device and detection method - Google Patents

Abstract

The invention relates to the technical field of soil heavy metal detection, in particular to a heavy metal soil detection device and a detection method, wherein the heavy metal soil detection device comprises a bottom plate, an outer shell is fixedly connected to the middle position of the upper surface of the bottom plate, and an upper cover is arranged on the upper edge of the outer shell; the middle position of the inner bottom of the outer shell is fixedly connected with a crucible table, and an electric heating plate is arranged at the position, close to the crucible table, of the bottom of the outer shell; crucible grooves are uniformly distributed in the crucible table, and crucibles are placed in the crucible grooves; and an acid adding mechanism is arranged on one side of the upper surface of the bottom plate. In addition, due to the arrangement of the plurality of crucibles, a large batch of soil experimental samples can be detected simultaneously, the advantage of open digestion is reserved, and the practicability of the device is improved.

Description

Heavy metal soil detection device and detection method

Technical Field

The invention relates to the technical field of soil heavy metal detection, in particular to a heavy metal soil detection device and a detection method.

Background

The soil inorganic pollutants are relatively prominent in heavy metals, and the heavy metals are easy to accumulate and are converted into methyl compounds with higher toxicity because the heavy metals cannot be decomposed by soil microorganisms, and even some of the heavy metals are accumulated in a human body through a food chain at harmful concentration and seriously harm the health of the human body, so that the analysis of the content of the heavy metals in the soil has important practical significance.

The method for measuring the heavy metals in the soil at the present stage comprises the following steps: the method comprises the steps of performing chemical analysis, optical analysis, electrochemical analysis, chromatographic analysis, atomic absorption and the like, wherein when the soil heavy metal detection means commonly used at present is used for detecting, soil components, especially the content of heavy metal elements, need to be cleared up due to the complexity of a soil structure, so that the mineral crystal lattices of the soil can be thoroughly destroyed, all elements to be detected in a sample enter a test solution, and then obtaining a clear and transparent water solution which is cleared up completely and suitable for instrument detection, and then analyzing the water solution by a corresponding analyzer.

The existing digestion method mainly comprises three types of open digestion, high-temperature closed digestion and microwave digestion, wherein the open digestion is widely applied, and the operation steps are as follows: firstly, weighing a sample; secondly, adding hydrochloric acid into the sample for low-temperature digestion; thirdly, adding nitric acid, hydrofluoric acid and perchloric acid in sequence; fourthly, covering and heating for pre-digestion; fifthly, opening the cover, heating by using an electric heating plate to drive acid to perchloric acid and smoke; sixthly, heating and extracting salts by using nitric acid or hydrochloric acid; and seventhly, testing the digestion solution by using an analyzer.

Open digestion process, prior art mainly relies on the manual work to carry out the interpolation of reagents such as strong acid, and strong acid has stronger corrosivity, operation process danger coefficient is high, make staff's personal safety have great hidden danger, to this technical problem, chinese patent application No. CN112730020A, a soil metal digestion device provides a novel digestion device, can automatically carry out the interpolation of reagent and can automatically stir its mixture simultaneously, thus has avoided the potential safety hazard that the manual contact strong acid brought, but in the actual use process, according to the normal every 0.25-0.5 gram soil sample need each kind of acid volume of adding not more than several milliliters, digestion process has the acid variety that adds at every turn many, the quantity is few characteristics, contrast patent is because only one digestions the liquid case, still need the manual work to add various strong acid reagents to digesting the liquid case at different time quantum respectively, the technical problem is not fundamentally solved, in addition, the defect that mass soil sample detection cannot be carried out at one time exists in the contrast patent, the advantage that mass detection can be carried out by open digestion is lost, and the practicability of the digestion method is reduced.

Therefore, a heavy metal soil detection device and a detection method are provided.

Disclosure of Invention

The invention aims to provide a heavy metal soil detection device and a detection method, which aim to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a heavy metal soil detection device comprises a bottom plate,

the middle position of the upper surface of the bottom plate is fixedly connected with an outer shell, and the upper edge of the outer shell is provided with an upper cover; the middle position of the inner bottom of the outer shell is fixedly connected with a crucible table, and an electric heating plate is arranged at the position, close to the crucible table, of the bottom of the outer shell; crucible grooves are uniformly distributed in the crucible table, and crucibles are placed in the crucible grooves; an acid adding mechanism is arranged on one side of the upper surface of the bottom plate;

the acid adding mechanism comprises a supporting rod which is connected to one side of the upper surface of the bottom plate in a sliding manner; the upper end of the supporting rod is fixedly connected with the mounting plate; the middle position of the lower surface of the mounting plate is connected with a first telescopic rod in a sliding mode, and the projection of a sliding track of the first telescopic rod and the projection of a sliding track of the support rod on the bottom plate are perpendicular to each other; the lower end of the first telescopic rod is fixedly connected with a connecting block, and the upper surface of the connecting block is fixedly connected with a stepping motor at a position close to the first telescopic rod; the lower surface of the connecting block is fixedly connected with a strong acid reagent adding mechanism, the lower surface of the strong acid reagent adding mechanism is fixedly connected with a liquid guide pipe, and the upper end of the liquid guide pipe is provided with a pipeline flow meter.

Preferably, the strong acid reagent adding mechanism comprises a transmission shaft fixedly connected with an output shaft of the stepping motor, and the lower end of the transmission shaft penetrates through the connecting block and is fixedly connected with the second telescopic rod; the lower end of the second telescopic rod is fixedly connected with a reagent table through threads; the upper surface of the reagent table is annularly provided with uniformly distributed reagent grooves; acid outlet mechanisms are arranged at the bottoms of the reagent tanks; the edge position of the lower surface of the connecting block is fixedly connected with the housing through threads; the liquid guide pipe is fixedly connected to the lower surface of the housing through threads, and the distance between the liquid guide pipe and the center of the lower surface of the connecting block is equal to the radius of a circular ring formed by the uniformly distributed acid outlet mechanisms.

Preferably, the acid outlet mechanism comprises a hollow frame fixedly connected to the top end inside the liquid guide pipe; the middle position of the upper surface of the hollow frame is fixedly connected with an ejector rod; the position of the lower surface of the cover shell, which is close to the liquid guide pipe, is fixedly connected with a horn-shaped outer edge; the lower surface of the reagent table is provided with uniformly distributed acid outlets corresponding to the reagent grooves, and the acid outlets are internally provided with holes and communicated with the reagent table; the bottom in the reagent tank is fixedly connected with a cylinder body at a position close to the corresponding acid outlet; the inner top of the cylinder body is fixedly connected with a first spring, and the lower end of the first spring is fixedly connected with a blocking block; the outer circle surface of the cylinder body is provided with first acid outlet holes which are uniformly distributed in an annular mode at positions corresponding to the blocking blocks, and the first acid outlet holes can be blocked by the blocking blocks when the first spring is in an original length state.

Preferably, the outer surface of the acid outlet is of an inverted circular truncated cone structure, and when the acid outlet mechanism works, the outer surface of the acid outlet can be attached to the horn-shaped outer edge to seal the connection position.

Preferably, the hole bottom end of the acid outlet communicated with the reagent table is of a horn-shaped structure, so that the ejector rod can rapidly enter the hole inside the acid outlet and communicated with the reagent table when the acid outlet mechanism works conveniently.

Preferably, the acid outlet mechanism comprises an acid outlet pipe fixedly connected to the bottom end of the reagent tank, and the acid outlet pipe is communicated with the reagent tank; a movable groove is formed in the side wall of the acid outlet pipe; the inner top of the movable groove is fixedly connected with a second spring, and the lower ends of the second springs are fixedly connected with the connecting cylinder together; the lower end of the connecting cylinder extends out of the movable groove and is fixedly connected with the mounting cylinder; a liquid outlet pipe is fixedly connected to the middle position inside the mounting cylinder, the upper end of the liquid outlet pipe penetrates through the acid pipe and extends into the acid pipe, a second acid outlet hole is formed in the upper end of the outer surface of the liquid outlet pipe in an annular shape, and the second acid outlet hole is in a state of being blocked by the bottom wall of the acid outlet pipe when the second spring is in an original length state; the bottom end of the inner surface of the cover shell is provided with a cylindrical outer cover corresponding to the position of the liquid guide pipe, and the bottom end of the cylindrical outer cover is communicated with the liquid guide pipe.

Preferably, one end of the liquid outlet pipe extending to the interior of the acid outlet pipe is fixedly connected with a sealing cover; and the bottom wall of the acid outlet pipe is provided with a sealing groove corresponding to the sealing cover.

Preferably, an acid vapor purification mechanism is arranged in the middle of the inner top surface of the upper cover, and the acid vapor purification mechanism comprises an installation shell fixedly connected with the middle of the inner top surface of the upper cover; the lower surface of the mounting shell is provided with a suction fan; one end of the suction fan is fixedly connected with the air guide pipe, and one end of the air guide pipe extends into the installation shell and is fixedly connected with the condenser; the lower end of the condenser is connected with the liquid collecting tank through a pipeline; one end of the condenser is fixedly connected with the exhaust pipe, and one end of the exhaust pipe penetrates through the upper cover and is fixedly connected with the gas purifier.

Preferably, the lower end of the liquid collecting tank is fixedly connected with a liquid discharge pipe, and the lower end of the liquid discharge pipe extends to the outside of the mounting shell; and the upper end of the liquid discharge pipe is provided with a control valve.

A heavy metal soil detection method comprises the following steps:

s1: sampling soil of a target to be detected, and performing air drying and crushing after sampling to prepare an experimental sample;

s2, dividing the soil experiment sample subjected to wind drying and crushing in the step S1 into equal parts, and adding the equal parts into a crucible arranged in a crucible table in the outer shell;

s3: the acid adding mechanism is controlled to move by the control panel, so that the liquid guide pipe is aligned to an experimental sample needing acid adding, hydrochloric acid is added, and meanwhile, the electric heating plate is started to heat, and low-temperature digestion is carried out;

s4: after all the sample hydrochloric acid is added in the step S3, starting a strong acid reagent adding mechanism, sequentially adjusting the types of the added strong acid into nitric acid, hydrofluoric acid and perchloric acid, and respectively adding the nitric acid, hydrofluoric acid and perchloric acid into the experimental sample in the step S3;

s5: capping the experimental sample crucible after the step S4, and simultaneously heating and digesting the crucible by covering the upper cover;

s6: opening the cover, continuously heating by using an electric heating plate, and carrying out acid-dispelling and perchloric acid smoking on the experimental sample;

s7: adding nitric acid or hydrochloric acid into the experimental sample obtained in the step S6 by using an acid adding mechanism again, and extracting salts in the clarified liquid of the experimental sample;

s8: and (4) adding the clarified digestion solution experimental sample obtained in the step S7 into a digestion solution instrument to detect the heavy metal content.

Compared with the prior art, the invention has the beneficial effects that:

compared with the prior art, the automatic reagent adding device has the advantages that the acid adding mechanism is arranged, the reagent can be automatically added, potential safety hazards caused by manual strong acid contact are reduced, and the safety of digestion process operation is improved.

Drawings

FIG. 1 is a flow chart of the detection of the present invention;

FIG. 2 is a schematic view of the overall structure of the present invention;

FIG. 3 is a cross-sectional structural view of the present invention;

FIG. 4 is a cross-sectional view of the strong acid reagent addition mechanism of the present invention;

FIG. 5 is an enlarged structural view of one embodiment of the acid discharge mechanism of the present invention;

FIG. 6 is an enlarged structural view taken at A in FIG. 5 in accordance with the present invention;

FIG. 7 is a view of the connection structure of the catheter of the present invention with the flared rim;

FIG. 8 is an enlarged structural view of another embodiment of the acid discharge mechanism of the present invention;

FIG. 9 is an enlarged structural view taken at B in FIG. 8 in accordance with the present invention;

fig. 10 is an enlarged structural view of the acid vapor purification mechanism of the present invention.

In the figure: 1. a base plate; 2. a support bar; 3. mounting a plate; 4. a first telescopic rod; 5. a strong acid reagent addition mechanism; 51. a drive shaft; 52. a second telescopic rod; 53. a reagent table; 54. a reagent tank; 55. a housing; 56. an acid outlet mechanism; 561. hollowing out the frame; 562. a top rod; 563. a flared outer edge; 564. an acid outlet; 565. a barrel; 566. a first spring; 567. a first acid outlet hole; 568. blocking; 569. an acid outlet pipe; 570. a second spring; 571. a movable groove; 572. a connecting cylinder; 573. a liquid outlet pipe; 574. mounting the cylinder; 575. a cylindrical housing; 576. a sealing cover; 577. a sealing groove; 578. a second acid outlet hole; 6. a stepping motor; 7. connecting blocks; 8. a catheter; 9. an upper cover; 10. an outer housing; 11. an acid vapor purification mechanism; 111. mounting a shell; 112. a suction fan; 113. a liquid collecting tank; 114. a condenser; 115. a gas purifier; 116. a liquid discharge pipe; 117. a control valve; 12. a crucible; 13. a crucible table; 14. an electrical heating plate; 15. a pipeline flowmeter.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. Furthermore, the terms "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

A heavy metal soil detection device is shown in figures 1 to 7 and 10 and comprises a bottom plate 1, wherein an outer shell 10 is fixedly connected to the middle position of the upper surface of the bottom plate 1, and an upper cover 9 is arranged on the upper edge of the outer shell 10; a crucible table 13 is fixedly connected to the middle position of the inner bottom of the outer shell 10, and an electric heating plate 14 is arranged at the position, close to the crucible table 13, of the bottom of the outer shell 10; a uniformly distributed crucible groove is formed in the crucible table 13, and the crucible 12 is placed in the crucible groove; an acid adding mechanism is arranged on one side of the upper surface of the bottom plate 1; the acid adding mechanism comprises a supporting rod 2 which is connected to one side of the upper surface of the bottom plate 1 in a sliding manner; the upper end of the support rod 2 is fixedly connected with the mounting plate 3; the middle position of the lower surface of the mounting plate 3 is connected with a first telescopic rod 4 in a sliding mode, and the projection of the sliding track of the first telescopic rod 4 and the projection of the sliding track of the support rod 2 on the bottom plate 1 are perpendicular to each other; the lower end of the first telescopic rod 4 is fixedly connected with a connecting block 7, and the upper surface of the connecting block 7 is fixedly connected with a stepping motor 6 at a position close to the first telescopic rod 4; the lower surface of the connecting block 7 is fixedly connected with a strong acid reagent adding mechanism 5, the lower surface of the strong acid reagent adding mechanism 5 is fixedly connected with a liquid guide pipe 8, and the upper end of the liquid guide pipe 8 is provided with a pipeline flow meter 15.

By arranging the acid adding mechanism, when adding acid, the slide block connected with the support rod 2 can be controlled to slide in the chute by the control panel arranged on the outer shell 10, so that the liquid guide tube 8 can be aligned to the first row of crucibles 12 in the crucible table 13, after the movement is finished, the strong acid reagent adding mechanism 5, the connecting block 7 and the liquid guide tube 8 are controlled to move by the control panel according to the same principle, so that the liquid guide tube 8 is aligned to the initial station of the first row of crucibles 12, after the liquid guide tube 8 is calibrated to the initial station, the first telescopic rod 4 can be controlled to extend, so that the strong acid reagent adding mechanism 5 works to add strong acid, the amount of added acid can be detected by the pipeline flowmeter 15, after the acid adding amount is reached, the strong acid reagent adding mechanism 5 is closed, the current acid reagent adding of the crucibles 12 is finished, the acid adding is started from the initial station, and the control panel automatically moves the acid adding mechanism according to the coordinate position preset by the system, the liquid guide pipe 8 is driven to add the current type of strong acid to all the crucibles 12 one by one, after the addition of the current type of strong acid is completed, when the acid needs to be changed, the strong acid reagent adding mechanism 5 can be controlled to switch the current type of the added strong acid, so that the proper type of strong acid is in a working state, the addition of different strong acid types of reagents is performed to all the crucibles 12 according to the method, the adding process of the strong acid in the digestion process can be completed, compared with the prior art, the reagent can be automatically added, the potential safety hazard brought by manual contact of the strong acid is reduced, the operation safety of the digestion process is improved, compared with a comparison patent, the acid adding mechanism provided by the invention can realize the automatic switching of different types of strong acid reagents, the different types of acid are not required to be frequently added into a strong acid storage tank manually, and the potential safety hazard brought by manual contact of the strong acid is fundamentally solved, in addition, the plurality of crucibles 12 are arranged, so that a large batch of soil experiment samples can be detected at the same time, the advantage of open digestion is kept, and the practicability of the device is improved.

As shown in fig. 3, the strong acid reagent adding mechanism 5 includes a transmission shaft 51 fixedly connected to an output shaft of the stepping motor 6, and a lower end of the transmission shaft 51 penetrates through the connection block 7 and is fixedly connected to a second telescopic rod 52; the lower end of the second telescopic rod 52 is fixedly connected with a reagent table 53 through threads; the upper surface of the reagent table 53 is annularly provided with reagent grooves 54 which are uniformly distributed; acid outlet mechanisms 56 are arranged at the bottoms of the reagent tanks 54; the edge position of the lower surface of the connecting block 7 is fixedly connected with the housing 55 through threads; the liquid guide pipe 8 is fixedly connected to the lower surface of the housing 55 through threads, and the distance from the liquid guide pipe 8 to the center of the lower surface of the connecting block 7 is equal to the radius of a circular ring formed by the uniformly distributed acid outlet mechanisms 56.

The strong acid reagent adding mechanism 5 switches the types of different strong acids, so that the strong acid reagent adding mechanism meets the current acid adding requirement, the second telescopic rod 52 is firstly controlled to be shortened, the acid adding state of the strong acid reagent adding mechanism 5 is closed, then the control panel can control the operation of the stepping motor 6, the output shaft of the stepping motor 6 drives the fixedly connected transmission shaft 51 to rotate, the second telescopic rod 52 and the reagent table 53 fixedly connected with the transmission shaft 51 are further driven to rotate, when the strong acid reagent is to be rotated to the type of the strong acid to be added, at the moment, the acid outlet mechanism 56 at the bottom of the reagent groove 54 corresponding to the type of the strong acid to be added is opened, the strong acid reagent is led out from the catheter 8, and then the switching of the types of the different strong acids is completed.

As shown in fig. 5 and 6, the acid outlet mechanism 56 includes a hollow frame 561 fixedly connected to the inner top end of the catheter 8; the middle position of the upper surface of the hollow frame 561 is fixedly connected with a mandril 562; the lower surface of the cover shell 55 is fixedly connected with a flared outer edge 563 at the position close to the liquid guide pipe 8; the lower surface of the reagent table 53 is provided with acid outlets 564 which are uniformly distributed at positions corresponding to the reagent grooves 54, and the acid outlets 564 are internally provided with holes and communicated with the reagent table 53; a cylinder body 565 is fixedly connected at the bottom in the reagent groove 54 near the position corresponding to the acid outlet 564; the inner top of the cylinder body 565 is fixedly connected with a first spring 566, and the lower end of the first spring 566 is fixedly connected with a block 568; the first acid outlet holes 567 are uniformly distributed in an annular shape at the position, corresponding to the blocking piece 568, of the outer circular surface of the cylinder body 565, and the blocking piece 568 can block the first acid outlet holes 567 when the first spring 566 is in the original length state.

When the acid outlet mechanism 56 works, firstly, the second telescopic rod 52 extends to drive the reagent table 53 to move downwards, at the moment, the ejector rod 562 mounted on the hollow frame 561 enters the reagent tank 54 from the hole formed in the acid outlet 564, the ejector rod 562 pushes the blocking block 568 to move upwards after entering the reagent tank 54, the first spring 566 is compressed, and then the first acid outlet 567 is leaked, at the moment, the corresponding strong acid in the reagent tank 54 flows out from the hole formed in the acid outlet 564, and the acid is added to the crucible 12 through the acid outlet 564 and the catheter 8, so that the acid outlet is completed.

As shown in fig. 5, the outer surface of the acid outlet 564 is of a rounded truncated cone structure, and when the acid outlet 56 operates, the outer surface of the acid outlet 564 can be attached to the flared outer edge 563 to seal the connection position.

When the acid outlet mechanism 56 adds acid, the connection position of the acid outlet 564 and the catheter 8 may cause leakage of strong acid due to poor sealing performance, and further, the accuracy of experimental data is affected.

As shown in fig. 5, the bottom end of the hole of the acid outlet 564 communicating with the reagent table 53 is in a trumpet-shaped structure, so that the top rod 562 can rapidly enter the hole of the acid outlet 564 communicating with the reagent table 53 when the acid outlet mechanism 56 works.

When the acid outlet mechanism 56 works, the top rod 562 needs to enter the reagent tank 54 from a hole formed in the acid outlet 564, and displacement deviation may exist due to external vibration in the moving process of the acid adding mechanism, so that the top rod 562 cannot enter the reagent tank 54 from the hole formed in the acid outlet 564, and finally the acid outlet mechanism 56 cannot work.

As shown in fig. 10, an acid vapor purification mechanism 11 is disposed at a middle position of an inner top surface of the upper cover 9, and the acid vapor purification mechanism 11 includes an installation shell 111 fixedly connected to the middle position of the inner top surface of the upper cover 9; a suction fan 112 is arranged on the lower surface of the mounting shell 111; one end of the suction fan 112 is fixedly connected with an air duct, and one end of the air duct extends into the installation shell 111 and is fixedly connected with the condenser 114; the lower end of the condenser 114 is connected with a liquid collecting tank 113 through a pipeline; one end of the condenser 114 is fixedly connected with an exhaust pipe, and one end of the exhaust pipe penetrates through the upper cover 9 and is fixedly connected with the gas purifier 115.

The lower end of the liquid collecting groove 113 is fixedly connected with a liquid discharge pipe 116, and the lower end of the liquid discharge pipe 116 extends to the outside of the mounting shell 111; the upper end of the drain pipe 116 is provided with a control valve 117.

According to the invention, by arranging the acid vapor purification mechanism 11, after acid vapor is evaporated, the suction fan 112 works to suck strong acid vapor into the condenser 114 through a pipeline, liquefy the acid mist in the condenser 114, and then the acid mist enters the liquid collecting tank 113 through the pipeline, meanwhile, the rest non-condensed gas is purified and discharged through the gas purifier 115, so that the experimenter is prevented from being injured by the acid vapor, the safety of the experiment is improved, in addition, after the experiment is finished, acid liquid in the liquid collecting tank 113 can be discharged through the liquid discharge pipe 116 by opening the control valve 117, and the cleaning is convenient.

A heavy metal soil detection method is suitable for the heavy metal soil detection device, and comprises the following steps:

s1: sampling soil of a target to be detected, and performing air drying and crushing after sampling to prepare an experimental sample;

s2, dividing the soil experiment sample subjected to air drying and crushing in the step S1 into equal parts, and adding the equal parts into a crucible 12 arranged in a crucible table 13 in the outer shell 10;

s3: the acid adding mechanism is controlled by the control panel to move, so that the liquid guide pipe 8 is aligned to an experimental sample needing acid adding, hydrochloric acid is added, and meanwhile, the electric heating plate 14 is started to heat, and low-temperature digestion is carried out;

s4: after all the sample hydrochloric acid is added in the step S3, starting a strong acid reagent adding mechanism 5, sequentially adjusting the types of the added strong acid into nitric acid, hydrofluoric acid and perchloric acid, and respectively adding the nitric acid, hydrofluoric acid and perchloric acid into the experimental sample in the step S3;

s5: capping the experimental sample crucible 12 which is finished with the step S4, and simultaneously, heating and digesting the crucible by capping the upper cover 9;

s6: opening the cover, continuously heating by using the electric heating plate 14, and carrying out acid-dispelling and perchloric acid smoking on the experimental sample;

s7: adding nitric acid or hydrochloric acid into the experimental sample obtained in the step S6 by using an acid adding mechanism again, and extracting salts in the clarified liquid of the experimental sample;

s8: and (4) adding the clarified digestion solution experimental sample obtained in the step S7 into a digestion solution instrument to detect the heavy metal content.

Example two

As shown in fig. 8 and 9, the difference between the second embodiment and the first embodiment is:

the acid outlet mechanism 56 comprises an acid outlet pipe 569 fixedly connected to the bottom end of the reagent tank 54, and the acid outlet pipe 569 is communicated with the reagent tank 54; a movable groove 571 is formed in the side wall of the acid outlet pipe 569; the inner top of the movable groove 571 is fixedly connected with a second spring 570, and the lower ends of the second springs 570 are fixedly connected with a connecting cylinder 572; the lower end of the connecting cylinder 572 extends out of a movable groove 571 and is fixedly connected with an installation cylinder 574; a liquid outlet pipe 573 is fixedly connected to the middle position in the installation cylinder 574, the upper end of the liquid outlet pipe 573 penetrates through the acid outlet pipe 569 and extends into the acid outlet pipe 573, a second acid outlet hole 578 is annularly formed in the upper end of the outer surface of the liquid outlet pipe 573, and the second acid outlet hole 578 is blocked by the bottom wall of the acid outlet pipe 569 when the second spring 570 is in the original length state; the bottom end of the inner surface of the cover 55 is provided with a cylindrical outer cover 575 corresponding to the position of the liquid guide tube 8, and the bottom end of the cylindrical outer cover 575 is communicated with the liquid guide tube 8.

One end of the liquid outlet pipe 573 extending into the acid outlet pipe 569 is fixedly connected with a sealing cover 576, and a sealing groove 577 is formed in the bottom wall of the acid outlet pipe 569 corresponding to the sealing cover 576.

When the acid outlet mechanism 56 works, the second telescopic rod 52 extends to drive the reagent table 53 to move downwards, the downward movement of the reagent table 53 drives the installation cylinder 574, the connecting cylinder 572 and the acid outlet pipe 569 to move downwards, when the mounting cylinder 574 enters and contacts the cylinder type outer cover 575, the second spring 570 starts to contract under the pressure, at this time, the reagent table 53 is still in a downward moving state, while the mounting barrel 574 and the connecting barrel 572 remain stationary, so that the outlet pipe 573 gradually enters the interior of the acid outlet pipe 569, the acid outlet pipe 569 is communicated with the reagent tank 54, so that the strong acid in the reagent tank 54 flows out through a second acid outlet hole 578 arranged at the upper end of the liquid outlet pipe 573 to finish acid outlet, one end of the liquid outlet pipe 573 extending to the interior of the acid outlet pipe 569 is fixedly connected with a sealing cover 576, and the bottom wall of the acid outlet pipe 569 corresponding to the sealing cover 576 is provided with a sealing groove 577, can ensure that the acid outlet mechanism 56 keeps good sealing performance when not working, and prevent strong acid from leaking from the connecting position of the liquid outlet pipe 573 and the acid outlet pipe 569.

The specific working process is as follows: firstly, a slide block connected with a support rod 2 is controlled to slide in a sliding chute through a control panel arranged on an outer shell 10, so that a liquid guide pipe 8 can be aligned to a first row of crucibles 12 in a crucible table 13, after the movement is finished, a strong acid reagent adding mechanism 5, a connecting block 7 and the liquid guide pipe 8 are controlled to move through the control panel according to the same principle, so that the liquid guide pipe 8 is aligned to an initial station of the first row of crucibles 12, after the liquid guide pipe 8 is calibrated to the initial station, the first telescopic rod 4 can be controlled to extend, so that the strong acid reagent adding mechanism 5 works to add strong acid, the amount of added acid can be detected through a pipeline flowmeter 15, after the amount of added acid is reached, the strong acid reagent adding mechanism 5 is closed, the current addition of the acid reagent to the crucibles 12 is finished, and the control panel automatically moves the acid adding mechanism according to a coordinate position preset by the system from the initial station, the liquid guide pipe 8 is driven to add the current type of strong acid to all the crucibles 12 one by one, after the addition of the current type of strong acid is completed, when the acid needs to be changed, the strong acid reagent adding mechanism 5 can be controlled to switch the current type of the added strong acid, so that the suitable type of strong acid is in a working state, the addition of different types of strong acid reagents is performed to all the crucibles 12 according to the method, and the adding process of the strong acid in the digestion process can be completed.

The electric elements in the document are electrically connected with an external main controller and 220V mains supply through a transformer, the main controller can be a conventional known device controlled by a computer and the like, the product model provided by the invention is only used according to the structural characteristics of the product, the product can be adjusted and modified after being purchased, so that the product is more matched with and accords with the technical scheme of the invention, the product model is a technical scheme of the optimal application of the technical scheme, the product model can be replaced and modified according to the required technical parameters, and the product model is familiar to the technical personnel in the field, so that the technical scheme provided by the invention can clearly obtain the corresponding use effect.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A heavy metal soil detection device, which comprises a detection device,

including bottom plate (1), its characterized in that:

the middle position of the upper surface of the bottom plate (1) is fixedly connected with an outer shell (10), and the upper edge of the outer shell (10) is provided with an upper cover (9); the middle position of the inner bottom of the outer shell (10) is fixedly connected with a crucible table (13), and an electric heating plate (14) is arranged at the position, close to the crucible table (13), of the bottom of the outer shell (10); crucible grooves are uniformly distributed in the crucible table (13), and crucibles (12) are placed in the crucible grooves; an acid adding mechanism is arranged on one side of the upper surface of the bottom plate (1);

the acid adding mechanism comprises a water tank,

a support rod (2) which is connected with one side of the upper surface of the bottom plate (1) in a sliding way; the upper end of the support rod (2) is fixedly connected with the mounting plate (3); the middle position of the lower surface of the mounting plate (3) is connected with a first telescopic rod (4) in a sliding mode, and the projection of a sliding track of the first telescopic rod (4) and the projection of a sliding track of the support rod (2) on the bottom plate (1) are perpendicular to each other; the lower end of the first telescopic rod (4) is fixedly connected with a connecting block (7), and the position, close to the first telescopic rod (4), of the upper surface of the connecting block (7) is fixedly connected with a stepping motor (6); the lower surface of the connecting block (7) is fixedly connected with a strong acid reagent adding mechanism (5), the lower surface of the strong acid reagent adding mechanism (5) is fixedly connected with a liquid guide pipe (8), and the upper end of the liquid guide pipe (8) is provided with a pipeline flow meter (15).

2. The heavy metal soil detection device of claim 1, wherein: the strong acid reagent adding mechanism (5) comprises a transmission shaft (51) fixedly connected with an output shaft of the stepping motor (6), and the lower end of the transmission shaft (51) penetrates through the connecting block (7) and is fixedly connected with a second telescopic rod (52); the lower end of the second telescopic rod (52) is fixedly connected with a reagent table (53) through threads; the upper surface of the reagent table (53) is annularly provided with uniformly distributed reagent grooves (54); acid outlet mechanisms (56) are arranged at the bottoms of the reagent tanks (54); the edge position of the lower surface of the connecting block (7) is fixedly connected with a housing (55) through threads; the liquid guide pipe (8) is fixedly connected to the lower surface of the housing (55) through threads, and the distance between the liquid guide pipe (8) and the center of the lower surface of the connecting block (7) is equal to the radius of a circular ring formed by the uniformly distributed acid outlet mechanisms (56).

3. The heavy metal soil detection device of claim 2, wherein: the acid outlet mechanism (56) comprises a hollow frame (561) fixedly connected to the top end inside the liquid guide pipe (8); the middle position of the upper surface of the hollow frame (561) is fixedly connected with a mandril (562); the position of the lower surface of the housing (55) close to the liquid guide pipe (8) is fixedly connected with a horn-shaped outer edge (563); the lower surface of the reagent table (53) is provided with acid outlets (564) which are uniformly distributed at positions corresponding to the reagent grooves (54), and the acid outlets (564) are internally provided with holes and communicated with the reagent table (53); the bottom in the reagent groove (54) is fixedly connected with a cylinder body (565) at a position close to the corresponding acid outlet (564); the inner top of the cylinder body (565) is fixedly connected with a first spring (566), and the lower end of the first spring (566) is fixedly connected with a block (568); the outer circle surface of the cylinder body (565) is provided with first acid outlet holes (567) which are uniformly distributed in an annular shape at positions corresponding to the blocking blocks (568), and the blocking blocks (568) can block the first acid outlet holes (567) when the first spring (566) is in an original length state.

4. The heavy metal soil detection device of claim 3, wherein: the outer surface of the acid outlet (564) is of an inverted circular truncated cone structure, and when the acid outlet mechanism (56) works, the outer surface of the acid outlet (564) can be attached to the horn-shaped outer edge (563) to seal the connection position.

5. The heavy metal soil detection device of claim 3, wherein: the bottom end of the hole of the acid outlet (564) communicated with the reagent table (53) is of a horn-shaped structure, so that the ejector rod (562) can rapidly enter the hole of the acid outlet (564) communicated with the reagent table (53) when the acid outlet mechanism (56) works.

6. The heavy metal soil detection device of claim 2, wherein: the acid outlet mechanism (56) comprises an acid outlet pipe (569) fixedly connected to the bottom end of the reagent groove (54), and the acid outlet pipe (569) is communicated with the reagent groove (54); a movable groove (571) is formed in the side wall of the acid outlet pipe (569); the inner top of the movable groove (571) is fixedly connected with a second spring (570), and the lower ends of the second springs (570) are fixedly connected with a connecting cylinder (572) together; the lower end of the connecting cylinder (572) extends out of a movable groove (571) and is fixedly connected with an installation cylinder (574); a liquid outlet pipe (573) is fixedly connected to the middle position in the installation cylinder (574), the upper end of the liquid outlet pipe (573) penetrates through the acid outlet pipe (569) and extends into the acid outlet pipe, a second acid outlet hole (578) is annularly formed in the upper end of the outer surface of the liquid outlet pipe (573), and the second acid outlet hole (578) is blocked by the bottom wall of the acid outlet pipe (569) when the second spring (570) is in an original length state; the bottom end of the inner surface of the cover shell (55) is provided with a cylindrical outer cover (575) corresponding to the position of the liquid guide pipe (8), and the bottom end of the cylindrical outer cover (575) is communicated with the liquid guide pipe (8).

7. The heavy metal soil detection device of claim 6, wherein: one end of the liquid outlet pipe (573) extending to the interior of the acid outlet pipe (569) is fixedly connected with a sealing cover (576); and the bottom wall of the acid outlet pipe (569) is provided with a sealing groove (577) corresponding to the sealing cover (576).

8. The heavy metal soil detection device of claim 1, wherein: an acid vapor purification mechanism (11) is arranged at the middle position of the inner top surface of the upper cover (9), and the acid vapor purification mechanism (11) comprises an installation shell (111) fixedly connected with the middle position of the inner top surface of the upper cover (9); a suction fan (112) is arranged on the lower surface of the mounting shell (111); one end of the suction fan (112) is fixedly connected with the air guide pipe, and one end of the air guide pipe extends into the mounting shell (111) and is fixedly connected with the condenser (114); the lower end of the condenser (114) is connected with a liquid collecting tank (113) through a pipeline; one end of the condenser (114) is fixedly connected with an exhaust pipe, and one end of the exhaust pipe penetrates through the upper cover (9) and is fixedly connected with the gas purifier (115).

9. The heavy metal soil detection device of claim 8, wherein: the lower end of the liquid collecting groove (113) is fixedly connected with a liquid discharge pipe (116), and the lower end of the liquid discharge pipe (116) extends to the outside of the mounting shell (111); the upper end of the liquid discharge pipe (116) is provided with a control valve (117).

10. The heavy metal soil detection method is characterized by comprising the following steps:

s1: sampling soil of a target to be detected, and performing air drying and crushing after sampling to prepare an experimental sample;

s2, dividing the soil experiment sample subjected to wind drying and crushing in the step S1 into equal parts, and adding the equal parts into a crucible (12) arranged in a crucible table (13) in the outer shell (10);

s3: the acid adding mechanism is controlled to move by the control panel, so that the liquid guide pipe (8) is aligned to an experimental sample needing acid adding, hydrochloric acid is added, and meanwhile, the electric heating plate (14) is started to heat, and low-temperature digestion is carried out;

s4: after all the sample hydrochloric acid is added in the step S3, starting a strong acid reagent adding mechanism (5), sequentially adjusting the types of the added strong acid into nitric acid, hydrofluoric acid and perchloric acid, and respectively adding the nitric acid, hydrofluoric acid and perchloric acid into the experimental sample in the step S3;

s5: covering the experimental sample crucible (12) which is finished with the step S4, and simultaneously covering the upper cover (9) for heating and digesting;

s6: opening the cover, continuously heating by using an electric heating plate (14), and carrying out acid-dispelling and perchloric acid smoking on the experimental sample;

s7: adding nitric acid or hydrochloric acid into the experimental sample obtained in the step S6 by using an acid adding mechanism again, and extracting salts in the clarified liquid of the experimental sample;

s8: and (4) adding the clarified digestion solution experimental sample obtained in the step S7 into a digestion solution instrument to detect the heavy metal content.

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