CN110487852B - Conductive on-line ore pulp concentration measuring method - Google Patents
Conductive on-line ore pulp concentration measuring method Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
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- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/06—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a liquid
- G01N27/08—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a liquid which is flowing continuously
Abstract
The invention discloses an electric conduction type online ore pulp concentration measuring method, which belongs to the technical field of ore pulp concentration/density measurement and comprises at least two insulating connecting pipes and at least three electrode pipes, wherein the insulating connecting pipes and the electrode pipes are arranged at intervals, the insulating connecting pipes are arranged between two adjacent electrode pipes, the two adjacent electrode pipes are respectively connected with two end parts of the insulating connecting pipes, each electrode pipe comprises a liquid contact ring section, and only the liquid contact ring section in the whole electrode pipe is in contact with ore pulp during measurement. The invention applies the conductive on-line pulp concentration meter to the pulp concentration measurement work, and can more conveniently carry out the on-line measurement work on the pulp concentration, thereby avoiding the conditions of unsmooth connection or waste of transportation power between process sections and meeting the use requirements of mines on the on-line concentration/densimeter.
Description
Technical Field
The invention relates to the technical field of ore pulp concentration/density measurement, in particular to a conductive online ore pulp concentration measurement method.
Background
Most metallurgical mines adopt a wet grinding and sorting process to sort mined ores, and a plurality of grinding and sorting processes are adopted mostly. And conveying the ore pulp by adopting a pipeline pumping mode between the upstream grinding and selecting process and the downstream grinding and selecting process.
As there is a natural fluctuation in the grade of the original ore, there is also a natural fluctuation in the proportion of tailings (waste ore) that are rejected at the time of ore grade separation. The speed of ore being fed into the mill and the classifier is practically always lack of accurate control, so that the concentration of ore pulp conveyed among process sections has great fluctuation, and the condition of unsmooth connection among the process sections or waste of conveying power is caused. As such, mines have always had a realistic need for on-line pulp concentration/densitometers.
Conventionally, the mine mostly adopts manual sampling for measuring the concentration/density of ore pulp, and a densitometer is used for measuring the density of the ore pulp and calculating the volume concentration (volume fraction) of the ore pulp. The frequency of manual sampling is typically once an hour, and the sampling data is too long in time interval for real-time process control of production.
In fact, the application of an "on-line nuclear type concentration/density meter" has been widely popularized in metallurgical mines for a long time, and this type of meter usually adopts cesium 137 isotope as a radioactive source, so that when a ray bundle passes through a pulp pipeline, due to the absorption of the ray by a pulp substance, a received signal at a receiving end of the ray bundle is weakened, and the concentration/density of the pulp is measured. The half-life period of the cesium 137 is 30 years, the service life of a radioactive source even exceeds the service life of the instrument, the radiation dose rate is stable, and meanwhile, key devices in the measuring instrument are not in contact with ore pulp, so that the instrument has high stability and reliability in long-term operation and is trusted by users. However, various accidents are caused by the special hazard of radioactive materials, as well as by regulatory leaks. The state starts to adopt weapon-level standard control measures for radioactive sources in 2008, so that the instruments gradually quit mines.
After the nuclear type concentration/density meter exits the market, research units and corresponding meter manufacturers release the following steps: non-radioactive meters such as capacitance type concentration/densitometers, ultrasonic type concentration/densitometers, and string vibration type concentration/densitometers. Unfortunately, none of these meters have been so far effectively popularized and applied. Although the reasons are manifold, the failure of such meters to fully meet mine requirements for long term stability and reliability of operation by themselves is a major reason. Therefore, a conductive online ore pulp concentration measuring method is provided.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: how to more conveniently carry out on-line measurement work to ore pulp concentration to avoid appearing linking up smoothly or transporting the extravagant condition of power between the technology section, satisfy the mine and to the user demand of online densimeter, provide the online ore pulp concentration meter of conductance formula.
The invention solves the technical problems by the following technical scheme, and the invention comprises at least two insulating connecting pipes and at least three electrode pipes, wherein the insulating connecting pipes and the electrode pipes are arranged at intervals, the insulating connecting pipes are arranged between two adjacent electrode pipes, the two adjacent electrode pipes are respectively connected with two end parts of the insulating connecting pipes, each electrode pipe comprises a liquid contact ring section, and only the liquid contact ring section in the whole electrode pipe is contacted with ore pulp during measurement.
Furthermore, the quantity of insulating connecting pipe is two, the quantity of electrode tube is three, is located the centre when measuring electrode tube is in the high potential all the time, is located two at both ends electrode tube is in zero potential all the time. And adopted the online ore pulp concentration meter of conductance formula based on three electrodes two insulation tube structures, can make whole measurement circuit form the closed loop, the inside and outside electric signal crosstalk of ore pulp transportation pipeline can be effectively shielded, guarantee measuring stability and reliability, the ore pulp flows through the online ore pulp concentration meter of conductance formula and advances along one end all the time, from the other end play, the high potential region of the online ore pulp concentration meter of conductance formula is in the import of an insulation connecting pipe respectively, and the export of another insulation connecting pipe, consider the fortune that the ore pulp flows probably brings current, then this design can eliminate the influence that produces to the measuring result by fortune current well.
Furthermore, the electrode tube further comprises two groove sections, the liquid contact ring section is located between the two groove sections, and the liquid contact ring section and the two groove sections are integrally formed. The integrated part can ensure the structural strength of the electrode tube.
Furthermore, the groove section has a groove matching the outer diameter of the insulating connection pipe, and the end of the insulating connection pipe is embedded in the groove.
Furthermore, the inner diameter of the liquid contact ring section is equal to the inner diameter of the insulating connecting pipe. This ensures the accuracy of the measurement results.
The invention also provides a method for measuring the concentration of the ore pulp, which comprises the following steps:
s1: connecting the electrode tubes at two ends with the negative electrode of a constant voltage power supply, connecting the electrode tube in the middle with the positive electrode of the constant voltage power supply, and respectively obtaining the resistance R of the ore pulp liquid by assuming the solid particles in the ore pulp as insulating substances0And the resistance R of the slurry.
S2: assuming that the cross-sectional area of the inner cavity of the insulated connecting pipe is A0The effective cross-sectional area of solid particles (ore) in the ore pulp is A, wherein A is less than A0(ii) a Namely, the solid particles are equivalent to a continuous cylinder with the cross section area A; the resistance R of the ore pulp liquid can be obtained according to the conductor resistance calculation formula0：
Resistance of ore pulp R:
wherein rho is the resistivity of the ore pulp liquid and is a variable, and L is the ore pulp liquid and the length of the ore pulp;
s3: the following definitions are made:
wherein, taulIs the volume of liquid in the pulp, ml＝ρlτlIs the mass of the pulp liquid, where plIs the pulp liquid density, taulIs the liquid volume of the pulp, ms＝ρsτsIs the mass of ore in the pulp, where psIs the density of the ore, τsIs the volume of the ore;
s4: in combination with the definition of equation (3), since L is equal, the volume ratio is equivalent to the cross-sectional area ratio, equation (3) combines equations (1) and (2) to obtain a pulp volume concentration of:
similarly, combining the definition of equation (4) and the result of equation (6) can obtain the mass concentration of the ore pulp as follows:
similarly, the pulp density is obtained according to the definition of the formula (5) and the derivation of the correlation formula:
the volume concentration of the pulp, the mass concentration of the pulp, and the density of the pulp can be obtained according to the above equations (6), (7), and (8).
Furthermore, the density of the ore in the pulp and the density of the pulp liquid are calibrated before the measurement is carried out.
The invention also provides an ore pulp concentration measuring device which comprises two electric conduction type online ore pulp concentration meters and a rotational flow type solid-liquid separator, wherein the two electric conduction type online ore pulp concentration meters are respectively a first ore pulp concentration meter and a second ore pulp concentration meter, the inlet of the first ore pulp concentration meter is communicated with an ore pulp conveying pipeline, the rotational flow type solid-liquid separator comprises a conical centrifugal barrel, a feed inlet, an overflow port and a bottom flow port, the outlet of the first ore pulp concentration meter is communicated with the feed inlet of the rotational flow type solid-liquid separator, and the inlet of the second ore pulp concentration meter is connected with the overflow port of the rotational flow type solid-liquid separator. The conductivity type online ore pulp concentration meter is applied to ore pulp concentration measurement, so that the ore pulp concentration can be more conveniently measured online, the condition that the connection is not smooth or the transport power is wasted between process sections is avoided, and the use requirement of a mine on the online concentration/densimeter is met.
Furthermore, the ore pulp concentration measuring device further comprises an ore pulp sample barrel, the ore pulp sample barrel is arranged below the spiral-flow type solid-liquid separator, the bottom flow port of the spiral-flow type solid-liquid separator and the outlet of the second ore pulp concentration meter are connected with the ore pulp sample barrel, and the ore pulp sample which is measured is buffered in the ore pulp sample barrel and flows into the ore pulp groove.
Furthermore, an electric centrifugal fan blade is arranged on the central axis of the conical centrifugal barrel, and the electric centrifugal fan blade can accelerate vortex flow and increase centrifugal force.
Compared with the prior art, the invention has the following advantages: according to the conductivity type online ore pulp concentration meter, the conductivity type online ore pulp concentration meter is applied to ore pulp concentration measurement, so that the ore pulp concentration can be conveniently measured online, the condition of unsmooth connection or waste of transport power between process sections is avoided, and the use requirement of a mine on the online concentration/densimeter is met; and adopted the online ore pulp concentration meter of conductance formula based on three electrodes two insulation tube structures, can make whole measurement circuit form the closed loop, the inside and outside electric signal crosstalk of ore pulp transportation pipeline can be effectively shielded, guarantee measuring stability and reliability, the ore pulp flows through the online ore pulp concentration meter of conductance formula and advances along one end all the time, from the other end play, the high potential region of the online ore pulp concentration meter of conductance formula is in the import of an insulation connecting pipe respectively, and the export of another insulation connecting pipe, consider the fortune that the ore pulp flows probably brings current, then this design can eliminate the influence that produces to the measuring result by fortune current well.
Drawings
Figure 1 is a schematic diagram of resistance measurement of ore pulp in a second embodiment of the invention;
FIG. 2 is a schematic structural diagram of an online slurry concentration measuring device according to a second embodiment of the present invention;
FIG. 3 is a schematic view showing the structure of a slurry concentration meter according to a second embodiment of the present invention;
FIG. 4 is a schematic diagram of the operation principle of the cyclone solid-liquid separator in the second embodiment of the present invention.
In the figure: 1. a slurry transport line; 2. a pulp concentration meter; 3. a cyclonic solid-liquid separator; 31. a conical centrifuge bucket; 32. a feed inlet; 33. a underflow port; 34. an overflow port; 4. a pulp sample bucket; 5. a conductor electrode; 6. a quartz glass tube; 7. and a liquid contact ring section.
Detailed Description
The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.
The embodiment provides a technical scheme: on-line ore pulp concentration meter of conductance formula, including two insulating connecting pipes and three electrode tube, insulating connecting pipe with the electrode tube interval sets up, insulating connecting pipe sets up adjacent two between the electrode tube, adjacent two the electrode tube respectively with the both ends of insulating connecting pipe are connected, the electrode tube is including touching the liquid ring section, whole when measuring in the electrode tube only touch liquid ring section and ore pulp contact.
More specifically, the electrode tube located in the middle is always at a high potential during measurement, and the two electrode tubes located at the two ends are always at a zero potential. And the conductive type on-line ore pulp concentration meter based on the structure of the three-electrode two-insulation pipe is adopted, the whole measuring loop can form a closed loop, the electric signal crosstalk inside and outside the ore pulp conveying pipeline can be effectively shielded, the stability and the reliability of measurement are ensured, the ore pulp flows through the conductive type on-line ore pulp concentration meter and always enters along one end and exits from the other end, the high potential area of the conductive type on-line ore pulp concentration meter is respectively positioned at the inlet of one insulation connecting pipe and the outlet of the other insulation connecting pipe, the possible convection current brought by the flowing ore pulp is considered, and the design can well eliminate the influence of the convection current on the measuring result
More specifically, the electrode tube still includes two groove sections, touch liquid ring section is located two between the groove section, touch liquid ring section and two groove section are integrated into one piece. The integrated part can ensure the structural strength of the electrode tube.
More specifically, the groove section has a groove matching the outer diameter of the insulating connection pipe, and the end of the insulating connection pipe is embedded in the groove.
More specifically, the inner diameter of the liquid contact ring section is equal to the inner diameter of the insulating connecting pipe. This ensures the accuracy of the measurement results.
The embodiment also provides a pulp concentration measuring method, which comprises the following steps:
s1: connecting the electrode tubes at two ends with the negative electrode of a constant voltage power supply, connecting the electrode tube in the middle with the positive electrode of the constant voltage power supply, and respectively obtaining the resistance R of the ore pulp liquid by assuming the solid particles in the ore pulp as insulating substances0And the resistance R of the slurry.
S2: assuming that the cross-sectional area of the inner cavity of the insulated connecting pipe is A0The effective cross-sectional area of solid particles (ore) in the ore pulp is A, wherein A is less than A0(ii) a Namely, the solid particles are equivalent to a continuous cylinder with the cross section area A; the resistance R of the ore pulp liquid can be obtained according to the conductor resistance calculation formula0：
Resistance of ore pulp R:
wherein rho is the resistivity of the ore pulp liquid and is a variable, and L is the ore pulp liquid and the length of the ore pulp;
s3: the following definitions are made:
wherein, taulIs the volume of liquid in the pulp, ml＝ρlτlIs the mass of the pulp liquid, where plIs the pulp liquid density, taulIs a slurry of oreVolume of liquid, ms＝ρsτsIs the mass of ore in the pulp, where psIs the density of the ore, τsIs the volume of the ore;
s4: in combination with the definition of equation (3), since L is equal, the volume ratio is equivalent to the cross-sectional area ratio, equation (3) combines equations (1) and (2) to obtain a pulp volume concentration of:
similarly, combining the definition of equation (4) and the result of equation (6) can obtain the mass concentration of the ore pulp as follows:
similarly, the pulp density is obtained according to the definition of the formula (5) and the derivation of the correlation formula:
the volume concentration of the pulp, the mass concentration of the pulp, and the density of the pulp can be obtained according to the above equations (6), (7), and (8).
More specifically, the density of the ore in the slurry and the density of the slurry liquid are calibrated before the measurement is performed.
This embodiment still provides an ore pulp concentration measuring device, including the online ore pulp concentration meter of two conductances formulas, spiral-flow type solid-liquid separation ware, the online ore pulp concentration meter of two conductances formulas is first ore pulp concentration meter and second ore pulp concentration meter respectively, the import and the ore pulp pipeline intercommunication of first ore pulp concentration meter, spiral-flow type solid-liquid separation ware includes conical centrifuge bucket, feed inlet, overflow mouth and underflow opening, the export of first ore pulp concentration meter with spiral-flow type solid-liquid separation ware the feed inlet intercommunication, the import of second ore pulp concentration meter with spiral-flow type solid-liquid separation ware the overflow mouth links to each other. The conductivity type online ore pulp concentration meter is applied to ore pulp concentration measurement, so that the ore pulp concentration can be more conveniently measured online, the condition that the connection is not smooth or the transport power is wasted between process sections is avoided, and the use requirement of a mine on the online concentration/densimeter is met.
More specifically, ore pulp concentration measurement device still includes the ore pulp sample bucket, the ore pulp sample bucket sets up spiral-flow type solid-liquid separator's below, spiral-flow type solid-liquid separator the underflow opening the export of second ore pulp concentration meter all with the ore pulp sample bucket is connected, accomplishes that measured ore pulp sample buffers in the ore pulp sample bucket flows into in the ore pulp groove.
More specifically, the electric centrifugal fan blades are arranged on the central axis of the conical centrifugal barrel, and the electric centrifugal fan blades can accelerate eddy currents and increase centrifugal force.
Example two
This embodiment provides a pulp concentration meter, which is described in detail below.
First, applicable conditions
Any instrument has its own applicable conditions, as does the pulp concentration meter, and here is mainly the applicable requirement for the measurement object (pulp), and the following are the specific conditions of the pulp:
(1) the pressure of ore pulp is more than or equal to 0.5Kg/cm2(gauge pressure); the lowest temperature of the ore pulp can not be lower than the solidifying point, and the highest temperature is less than 100 ℃.
(2) The slurry must be a newtonian fluid. And must not be a non-newtonian fluid such as a bingham fluid. The concentration of the conveyed ore pulp is generally controlled (when the concentration is too high, water is appropriately supplemented) so that the mass concentration of the conveyed ore pulp is less than 70-60%, the mass concentration can be higher as the ore density is higher, and the upper limit requirement of the specific ore pulp concentration needs to be determined by field calibration.
(3) The slurry must be a two-phase solid-liquid flow or a simple liquid phase flow. The materials conveyed in the pipeline can also have certain gas besides the ore pulp, and the materials conveyed in the pipeline are changed into a solid, liquid and gas three-phase coexisting state at the moment. This would be extremely disadvantageous for on-line measurement of pulp concentration/density. In fact, a liquid level control device is arranged on the slurry tank at the upstream of the conveying pipeline, so that the inlet of the slurry pump is always positioned at the lower edge of the liquid level of the slurry tank, gas can be prevented from entering the conveying pipeline, and the condition of two-phase flow limitation is met.
It should be noted that: two-phase flow restriction does not mean that gas at a half point cannot exist in the ore pulp, and in fact, because the ore pulp vortex on the liquid level surface of the ore pulp tank can entrain a certain amount of gas to enter a conveying pipeline, and gas can also be generated by natural evaporation of the ore pulp in the pipeline. The gas cannot be prevented, and the influence of the gas on the measurement result can be eliminated or greatly reduced by taking proper measures, such as the installation of an automatic exhaust device at the measuring section, wherein the two-phase flow restriction means that a large amount of gas cannot be generated in a conveying pipeline.
Second, measurement implementation mode
(1) General statements
The pulp consists of two parts of substances:
the first is a liquid substance, the main component of the substance is water, and acid, alkali or other substances are dissolved in the water, so that the conductivity of the liquid substance is high, the typical value is 1s/m, and it should be noted that the conductivity of the liquid substance in the pulp is not only high, but also the change amplitude and frequency are fast.
The second is solid particles, which are typically oxides of metals such as ferric oxide, ferric dioxide, cupric oxide, cuprous oxide, and the like, plus ore surrounding rock. The electrical conductivity of these solid particles is typically more than two orders of magnitude less than that of the liquid material. Experiments show that: the conductivity of the solid particles is negligible in the measurement or the solid particles can be considered as insulators compared to the liquid in the pulp, so that the measurement error is in most cases not more than ± 0.2%.
(2) Principle of measurement
The resistance R of the ore pulp and the resistance R of the separated ore pulp liquid are measured simultaneously and respectively by adopting a relative measurement mode through a tubular container provided with electrodes0。
As shown in figure 1, which is a measuring principle diagram of ore pulp resistance, a columnar electrode 5 made of wear-resistant stainless steel is respectively arranged at two ends of a quartz glass tube 6, and the cross-sectional area of the inner cavity of the quartz glass tube 6 is A0Assuming that the effective cross-sectional area of the solid particles in the ore pulp in the quartz glass tube 6 is A, namely the solid particles are equivalent to a continuous cylinder with the cross-sectional area A; note that A is less than A0A constant voltage power supply is connected between the two columnar electrodes 5, so as to respectively obtain the resistance R of the ore pulp liquid0And resistance of the slurry R (assuming the solid particles in the slurry are insulating material), there is a liquid resistance of:
ρ in the formula (1) is the resistivity of the pulp liquid, which is a variable.
The resistance of the ore pulp is:
as defined below:
first, the pulp volume concentration (or called pulp volume fraction)
τ in formula (3)lIs the volume of liquid in the slurry.
Second, the mass concentration of the ore pulp (or called the mass fraction of the ore pulp)
Third, pulp density
M in the formulae (4) and (5)l＝ρlτlIs the mass of the pulp liquid, where plIs the pulp liquid density, taulIs the liquid volume of the slurry. And m iss＝ρsτsThe mass of ore in the pulp (mass of solid particles in the pulp), where psIs the density of the solid particles, τsIs the volume of the solid particles.
Combining the definition of the formula (3), since the lengths are the same, the volume ratio is equivalent to the sectional area ratio, and the formula (1) and the formula (2) are combined to obtain the pulp volume concentration as follows:
similarly, combining the definition of equation (4) and the result of equation (6) can obtain the mass concentration of the ore pulp as follows:
similarly, the expression of the pulp density obtained according to the definition of the formula (5) and the derivation of the correlation formula is as follows:
thus, as long as the density of the ore (solid particles) in the slurry and the density of the slurry liquid (usually water) are calibrated in advance, the measurement process only needs to measure the resistance of the slurry and the resistance of the liquid separated from the slurry. Then, it is only necessary to calculate the following equations (6), (7) and (8) respectively: volume concentration of the ore pulp, mass concentration of the ore pulp, and density of the ore pulp.
The embodiment also provides an online pulp concentration measuring device, which is described in detail below.
Fig. 2 is a schematic structural diagram of an online pulp concentration measuring device. The ore pulp sample is continuously obtained by opening a hole on the side surface of the ore pulp conveying pipeline 1, two ore pulp concentration meters 2 are used for measuring the resistance of ore pulp and ore pulp liquid respectively, one ore pulp concentration meter 2 is arranged near an ore pulp sampling port, and the other ore pulp concentration meter 2 is arranged on the top end of the spiral-flow type solid-liquid separator 3. The cyclone solid-liquid separator 3 adopts a self-operated centrifugal separation method, and if necessary, electric centrifugal fan blades can be arranged on the central axis of the conical centrifugal barrel 31, so that the eddy is accelerated, and the centrifugal force is increased. The solid particles (which are denser) are caused to swirl downward along the bucket wall of the conical centrifugal bucket 31 under the action of centrifugal force, while the clarified liquid flows upward through another slurry concentration meter 2 along the internal rising vortex of the central axis of the cone, and finally the slurry sample which is measured is buffered in the slurry sample bucket 4 and flows into the slurry tank.
As shown in fig. 3, the structure of the conductivity type online slurry concentration meter is schematically illustrated, the concentration meter includes three cylindrical electrodes 5 and two sections of quartz glass tubes 6, the inside of the cylindrical electrode 5 is a cylindrical cavity, the two ends of the radius of the cylindrical cavity are large and the middle is small, and the small radius is a liquid contact ring section 7 of the cylindrical electrode 5, that is, only the ring section of the cylindrical electrode 5 is in contact with the slurry. The quartz material is used in view of its high wear resistance and electrical insulation properties.
Experiments show that the wear resistance of the electrode pipe diameter is a key index for measuring stability. The wear of the pipe diameter affects the measurement accuracy. Whereas the quartz glass tube 6 can well meet the use requirements.
By using a direct-current constant-voltage power supply, the middle electrode is always at a high potential, and the two electrodes at the two ends are always at zero potential. The resistance thus measured is the parallel resistance of two resistances in front and back of the pulp concentration meter 2. Such a design may produce the following effects:
the whole measuring circuit forms a closed loop, and the electric signal crosstalk inside and outside the pipeline can be effectively shielded, so that the stability and reliability of measurement are ensured;
the pulp flows through the pulp concentration meter 2 all the time along one end and out the other end. The high potential areas of the slurry concentration meter 2 are respectively arranged at the outlet of one quartz glass tube 6 and the inlet of the other quartz glass tube 6, and if the carrying current possibly brought by slurry flowing is considered, the design just eliminates the influence on the measuring result possibly caused by the carrying current.
FIG. 4 is a schematic view showing the operation principle of the cyclone solid-liquid separator. The inlet 32 is an inlet for sampling ore pulp, the inlet is arranged on one side of the upper edge of the conical centrifugal barrel 31 along the side wall, and the design enables the momentum of the advancing ore pulp to enter the cyclone solid-liquid separator 3 and then be converted into the angular momentum rotating around the conical side wall. The slurry makes a swirling descending motion in the conical centrifugal barrel 31, and the generated rotating centrifugal force makes the dense solid particles lean against the wall of the cyclone under the action of the external circulation, i.e. the solid particles slide down along the wall and flow out from the underflow port 33, while the liquid substance (slurry liquid) with low density forms an internal rotation flow and floats up to the top end of the cyclone and flows out from the overflow port 34.
In summary, the conductivity type online ore pulp concentration meters of the two embodiments can more conveniently perform online measurement on the ore pulp concentration by applying the conductivity type online ore pulp concentration meter to the ore pulp concentration measurement, thereby avoiding the situations of unsmooth connection or waste of transportation power between process sections and meeting the use requirements of mines on the online concentration/densitometer; and adopted the online ore pulp concentration meter of conductance formula based on three electrodes two insulation tube structures, can make whole measurement circuit form the closed loop, the inside and outside electric signal crosstalk of ore pulp transportation pipeline can obtain effective screen, guarantee measuring stability and reliability, the ore pulp flows through the online ore pulp concentration meter of conductance formula and advances along one end all the time, from the other end play, the high potential region of the online ore pulp concentration meter of conductance formula is in the import of an insulation connecting pipe respectively, and the export of another insulation connecting pipe, consider the fortune that the ore pulp flows probably brings current, then this design can eliminate the influence that produces to the measuring result by fortune current well, be worth being generalized to use.
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, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (9)
1. The conductivity type online ore pulp concentration measuring method is characterized in that the ore pulp concentration is measured online by using a conductivity type online ore pulp concentration meter, and the method comprises the following steps:
s1: connecting the electrode tubes at two ends with the negative electrode of a constant voltage power supply, connecting the electrode tube in the middle with the positive electrode of the constant voltage power supply, and respectively obtaining the resistance R of the ore pulp liquid by assuming the solid particles in the ore pulp as insulating substances0Resistance R with the ore pulp;
s2: the cross sectional area of the inner cavity of the insulating connecting pipe is A0The effective cross-sectional area of ore in the ore pulp is A, wherein A is less than A0(ii) a Namely, the ore is equivalent to a continuous cylinder with the cross section area of A; the resistance R of the ore pulp liquid can be obtained according to the conductor resistance calculation formula0：
Resistance of ore pulp R:
wherein rho is the resistivity of the ore pulp liquid and is a variable, and L is the ore pulp liquid and the length of the ore pulp;
s3: the initial expressions of the pulp volume concentration, the pulp mass concentration and the pulp density are obtained through the processing and are respectively as follows:
wherein, taulIs the volume of liquid in the pulp, ml＝ρlτlIs the mass of the pulp liquid, where plIs the pulp liquid density, taulIs the liquid volume of the pulp, ms＝ρsτsIs the mass of ore in the pulp, where psIs the density of the ore, τsIs the volume of the ore;
s4: since L is equal, the volume ratio is equivalent to the cross-sectional area ratio, and the final expression of the pulp volume concentration is obtained as follows:
the final expression of the mass concentration of the obtained ore pulp is as follows:
the final expression for the pulp density is obtained as:
calculating the volume concentration, mass concentration and density of the ore pulp according to the final expression of the parameters;
the online ore pulp concentration meter of conductance formula includes two at least insulation connecting pipe and three at least electrode tube, insulation connecting pipe with the electrode tube interval sets up, insulation connecting pipe sets up adjacent two between the electrode tube, adjacent two the electrode tube respectively with insulation connecting pipe's both ends are connected, the electrode tube is including touching the liquid ring section, whole when measuring in the electrode tube only touch the liquid ring section and ore pulp contact.
2. The conductive in-line pulp concentration measurement method of claim 1, characterized in that: the quantity of insulating connecting pipe is two, the quantity of electrode tube is three, is located the centre when measuring the electrode tube is in the high potential all the time, is located two at both ends the electrode tube is in zero potential all the time.
3. The conductive in-line pulp concentration measurement method of claim 1, characterized in that: the electrode tube further comprises two groove sections, the liquid contact ring section is located between the two groove sections, and the liquid contact ring section and the two groove sections are integrally formed.
4. The conductive in-line pulp concentration measurement method of claim 3, characterized in that: the groove section is provided with a groove matched with the outer diameter of the insulating connecting pipe, and the end part of the insulating connecting pipe is embedded in the groove.
5. The conductive in-line pulp concentration measurement method of claim 1, characterized in that: and the inner diameter of the liquid contact ring section is equal to that of the insulating connecting pipe.
6. The conductive in-line pulp concentration measurement method of claim 1, characterized in that: the insulating connecting pipe is a quartz pipe.
7. The conductive in-line pulp concentration measurement method of claim 1, characterized in that: before the measurement, the density of the ore in the ore pulp and the density of the ore pulp liquid are calibrated.
8. The conductive in-line pulp concentration measurement method according to any one of claims 1 to 6, characterized in that: the ore pulp concentration measuring device comprises two electric conduction type online ore pulp concentration meters and a spiral-flow type solid-liquid separator, wherein the two electric conduction type online ore pulp concentration meters are respectively a first ore pulp concentration meter and a second ore pulp concentration meter, the inlet of the first ore pulp concentration meter is communicated with an ore pulp transport pipeline, the spiral-flow type solid-liquid separator comprises a conical centrifugal barrel, a feed inlet, an overflow port and a bottom flow port, the outlet of the first ore pulp concentration meter is communicated with the spiral-flow type solid-liquid separator through the feed inlet, the inlet of the second ore pulp concentration meter is communicated with the spiral-flow type solid-liquid separator through the overflow port.
9. The conductive in-line pulp concentration measurement method of claim 8, characterized in that: the ore pulp concentration measuring device further comprises an ore pulp sample barrel, the ore pulp sample barrel is arranged below the spiral-flow type solid-liquid separator, the bottom flow port of the spiral-flow type solid-liquid separator and the outlet of the second ore pulp concentration meter are connected with the ore pulp sample barrel.
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