阅读说明：本技术 一种从含稀土钼酸盐中分离稀土和钼方法 (Method for separating rare earth and molybdenum from rare earth-containing molybdate ) 是由 李光辉 石大鹏 姜涛 孙虎 罗骏 饶明军 彭志伟 余俊杰 卜群真 张鑫 于 2019-05-20 设计创作，主要内容包括：本发明提供了一种从含稀土的钼酸盐中分离稀土和钼方法,将含稀土钼酸盐置于包含OH<Sup>-</Sup>、CO<Sub>3</Sub><Sup>2-</Sup>的联合浸出剂溶液中,再在100-160℃的温度下水热浸出,随后经固液分离,得富集含钼的碱浸液和富集有稀土的碱浸渣；所述的联合浸出剂溶液中,OH<Sup>-</Sup>的浓度为1～4moL/L；OH<Sup>-</Sup>/CO<Sub>3</Sub><Sup>2-</Sup>的摩尔比为1～4:1。本发明技术方案,可选择性地将稀土保留在浸出渣中,钼转移至浸出液中,且有效降低稀土的同步浸出量,显著提升稀土和钼的分离选择性,不仅如此,还能够有效提升稀土和钼各自的回收率。(The invention provides a method for separating rare earth and molybdenum from rare earth-containing molybdate, which is to put the rare earth-containing molybdate in a medium containing OH ‑ 、CO 3 2‑ In the combined leaching agent solution, performing hydrothermal leaching at the temperature of 100-160 ℃, and then performing solid-liquid separation to obtain molybdenum-enriched alkaline leaching solution and rare earth-enriched alkaline leaching residue; in the combined leaching agent solution, OH ‑ The concentration of (a) is 1-4 moL/L; OH group ‑ /CO 3 2‑ The molar ratio of (A) to (B) is 1-4: 1. According to the technical scheme, the rare earth can be selectively retained in the leaching slag, the molybdenum is transferred into the leaching solution, the synchronous leaching amount of the rare earth is effectively reduced, the separation selectivity of the rare earth and the molybdenum is remarkably improved, and the respective recovery rates of the rare earth and the molybdenum can be effectively improved.)

1. A process for separating rare earth and molybdenum from rare earth-containing molybdate, characterized in that rare earth-containing molybdate is exposed to OH^-、CO₃ ^2-Carrying out hydrothermal leaching at the temperature of 100-160 ℃ in the combined leaching agent solution, and then carrying out solid-liquid separation to obtain molybdenum-enriched alkaline leaching solution and rare earth-enriched alkaline leaching residue;

in the combined leaching agent solution, OH^-The concentration of (A) is 1-4 mol/L; OH group^-/CO₃ ^2-The molar ratio of (A) to (B) is 1-4: 1.

2. The method for separating rare earth and molybdenum from a rare earth-containing molybdate according to claim 1, wherein the rare earth element in the rare earth-containing molybdate is at least one of La, Ce and Nd;

preferably, in the rare earth-containing molybdate, the content of Mo is 5-10%, the content of La is 0.5-2.0%, the content of Ce is 0.5-3.0%, and the content of Nd is 0.2-1.0%;

preferably, the rare earth-containing molybdate also allows to contain at least one molybdate impurity of calcium, iron, lead and copper;

preferably, the rare earth-containing molybdate is high-temperature roasting-volatilization residual slag of rare earth-containing molybdenum concentrate, or rare earth-containing molybdenum calcine ammonia leaching residual slag; the slag contains at least one of mullite, quartz and corundum;

preferably, the particle size of the rare earth molybdate is not more than 80 μm; preferably 20 to 80 μm.

3. The method for separating rare earth and molybdenum from rare earth-containing molybdate according to claim 1 or 2, characterized in that the solid-to-liquid ratio of the rare earth-containing molybdate to the combined leaching agent solution is 1:4(g/mL) to 1:10 (g/mL).

4. The process for separating rare earth and molybdenum from rare earth-containing molybdates according to claim 1, wherein the OH in the combined leachant is^-Provided by an alkali metal hydroxide; the alkali metal hydroxide is at least one of sodium hydroxide and potassium hydroxide;

preferably, CO in the combined leachant₃ ^2-May be provided by a material which dissociates carbonate ions in aqueous solution, preferably a water soluble carbonate.

5. The method for separating rare earth and molybdenum from rare earth-containing molybdate according to claim 1, wherein the hydrothermal leaching time is 1 to 3 hours.

6. The method for separating rare earth and molybdenum from rare earth-containing molybdate according to claims 1 to 5, wherein the molybdenum is recovered from alkaline leaching solution extraction and back extraction by the steps of:

contacting the alkali leaching solution with an organic phase A, extracting, and separating to obtain an extraction phase enriched with molybdenum; contacting the extraction phase enriched with molybdenum with a stripping solution A, and performing stripping to obtain a stripping solution enriched with molybdenum;

the organic phase A comprises an extracting agent A, a diluent A and a phase modifier A; the extractant A is at least one of methyl trioctyl ammonium chloride and N263;

the diluent A is kerosene;

the phase modifier A is sec-octanol;

preferably, in the organic phase A, the proportion of the extracting agent A, the diluent A and the phase modifier A is 1-2: 5-10: 2-6;

in the process of extracting and recovering molybdenum from the alkaline leaching solution, the ratio of O/A to O/A is (0.5/1) - (2/1), the stirring speed is 600-800 r/min, the extraction time is 10-20 minutes, and the phase separation time is 10-20 minutes.

7. The process for separating rare earth and molybdenum from a rare earth-containing molybdate according to claim 6, wherein the stripping solution A is at least one of a sodium chloride solution, a sodium hydroxide solution and ammonia water;

the solute concentration of the back extraction solution A is 1-4 mol/L, the back extraction temperature is 20-50 ℃, and the back extraction time is 10-60 min.

8. The method for separating rare earth and molybdenum from rare earth-containing molybdate according to any one of claims 1 to 5, characterized in that the alkaline leaching residue is subjected to acid leaching treatment and then to solid-liquid separation to obtain acid leaching solution and acid leaching residue enriched with rare earth;

in the acid leaching process, the concentration of acid is 4-8 mol/L, the liquid-solid ratio is 4: 1-10: 1mL/g, the acid leaching time is 30-90 min, and the acid leaching temperature is 60-90 ℃.

9. The process for the separation of rare earth and molybdenum from rare earth-containing molybdates according to claim 8 wherein the rare earth is recovered from the acid leachate by extraction, stripping, the steps of: contacting the acid leaching solution with an organic phase B, extracting, separating to obtain an extraction phase rich in rare earth, and contacting the extraction phase with a back extraction solution B to obtain a back extraction solution rich in rare earth;

the organic phase B comprises an extracting agent B, a diluent B and a phase modifier B;

wherein the extractant B is at least one of P204, P305, P507 and N1923;

the diluent B is kerosene;

the phase modifier B is sec-octanol;

preferably, in the organic phase B, the proportion of the extractant B, the diluent B and the phase modifier B is 1-2: 2-10: 3-6;

in the process of extracting and recovering rare earth from acid leaching solution, the ratio of O/A is 0.5: 1-2: 1, the stirring speed is 600-800 r/min, the extraction time is 10-20 minutes, and the phase separation time is 10-20 minutes.

10. The method for separating rare earth and molybdenum from rare earth-containing molybdate according to claim 9, wherein the stripping solution B is hydrochloric acid with a concentration of 1 to 4mol/L, the stripping temperature is 20 to 50 ℃, and the stripping time is 10 to 60 min.

Technical Field

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for recovering molybdenum and rare earth elements from molybdate containing rare earth.

Background

Molybdenum is silver white refractory rare metal, has the advantages of high melting point (2620 ℃) and high boiling point (4804 ℃), high strength, corrosion resistance, grinding resistance and the like, has large electrical conductivity, good heat conduction performance and small expansion coefficient, is mainly used as an additive of steel, various high-temperature components in the aerospace industry, catalysts, semiconductor materials and the like, and has more than 20 molybdenum minerals found in nature, wherein the average content of molybdenum in earth crust is 1.1 × 10^-4% of the total weight of the composition. Wherein molybdenite is the most industrially valuable molybdenum mineral with the largest reserve.

Rare earth elements are known as industrial vitamins, have irreplaceable excellent magnetic, optical and electrical properties, and play a great role in improving product performance, increasing product varieties and improving production efficiency. Because of large action and small dosage of rare earth, the rare earth has become an important element for improving the product structure, improving the technological content and promoting the technical progress of the industry, and is widely applied to the fields of metallurgy, military, petrochemical industry, glass ceramics, agriculture, new materials and the like.

The carbonate vein type molybdenum ore deposit (such as Shanxi Huanglong shop large molybdenum ore deposit in China) is rich in important strategic metal minerals such as molybdenite, rhenium ore, monazite, bastnaesite, and easy-to-dissolve stone. After the mining and dressing treatment is carried out on the mineral product, the rare earth ore is enriched into the flotation molybdenum concentrate along with the molybdenite. Carrying out ammonia leaching on molybdenum calcine obtained by roasting rare earth-containing molybdenum concentrate, wherein rare earth and molybdate such as calcium, iron and the like are difficult to leach and remain in ammonia leaching slag; the rare earth-containing molybdenum concentrate is subjected to oxidation-volatilization treatment, so that rare earth and molybdate such as calcium, iron and the like are difficult to volatilize and remain in volatile slag.

The industrial treatment of rare earth-containing raw materials such as red mud is carried out by adding acid and then extracting and purifying by solvent. However, this method is not suitable for treating rare earth-containing molybdate tailings because when sufficient acid is added, molybdenum in the tailings will dissolve into the leach solution, which will result in lower purity of the rare earth salt solution and also interfere with the extraction separation of the rare earth elements. Therefore, the problem that the technical personnel in the field need to solve is how to effectively recover molybdenum element and recover rare earth elements rich in the molybdenum slag of the rare earth-containing molybdate tailings.

Disclosure of Invention

The present invention aims to solve the technical problems of the prior art, and an object of the present invention is to provide a method for separating rare earth and molybdenum from rare earth-containing molybdate, which aims to improve the separation selectivity of rare earth and molybdenum and improve the respective recovery rates.

The invention aims to fill the technical blank of separating rare earth and molybdenum from rare earth-containing molybdate, and provides a method for separating rare earth and molybdenum from rare earth-containing molybdate. However, to achieve this technical goal, the problem of selective separation of the two must be solved. In order to solve the technical problem, the invention provides the following technical scheme:

a method for separating rare earth and molybdenum from rare earth-containing molybdate comprises placing rare earth-containing molybdate in a container containing OH^-、CO₃ ^2-The combined leaching agent solution is subjected to hydrothermal leaching at the temperature of 100-160 ℃, and then solid-liquid separation is carried out to obtain alkali leaching solution enriched with molybdenum and alkali leaching solution enriched with rare earthSlag;

in the combined leaching agent solution, OH^-The concentration of (A) is 1-4 mol/L; OH group^-/CO₃ ^2-The molar ratio of (A) to (B) is 1-4: 1.

The inventor researches and discovers that the OH at the ratio is^-、CO₃ ^2-The combined hydrothermal leaching process can unexpectedly solve the technical problem that the leaching selectivity of rare earth and molybdenum is not high, the rare earth can be selectively retained in the leaching slag, the molybdenum is transferred into the leaching solution, the synchronous leaching amount of the rare earth is effectively reduced, the separation selectivity of the rare earth and the molybdenum is obviously improved, and the respective recovery rates of the rare earth and the molybdenum can also be effectively improved.

The rare earth element in the rare earth-containing molybdate is at least one of La, Ce and Nd. Preferably, the rare earth-containing molybdate contains 5-10% of Mo, 0.5-2.0% of La, 0.5-3.0% of Ce and 0.2-1.0% of Nd.

Preferably, the rare earth-containing molybdate also allows at least one molybdate impurity of calcium, iron, lead and copper.

Preferably, the rare earth-containing molybdate is residual slag of rare earth-containing molybdenum concentrate after high-temperature roasting-volatilization, or rare earth-containing molybdenum calcine, or residual slag of rare earth-containing molybdenum calcine after ammonia leaching. The slag contains mullite, quartz, corundum and other components.

Preferably, the particle size of the rare earth molybdate is not more than 80 μm; preferably 20 to 80 μm. Studies have found that good Mo and rare earth selectivity can be achieved while also unexpectedly increasing Mo recovery at the preferred particle size.

The key point of the invention is that (1) OH is adopted^-、CO₃ ^2-Combined leaching of (1); (2) to OH in a combined leaching system^-Concentration of (C) and OH^-/CO₃ ^2-The molar ratio is accurately controlled; (3) hydrothermal leaching at said temperature; through the synergy of the key parameters, the problem of non-ideal selectivity of rare earth and molybdenum is effectively solved, and the leaching selectivity and the recovery rate can be effectively improved.

Preferably, the raw material solutionOH in (1)^-Provided by an alkali metal hydroxide. It has been found that the OH is provided by alkali metal hydroxide^-The leaching selectivity can be further improved.

More preferably, the alkali metal hydroxide is at least one of sodium hydroxide and potassium hydroxide.

In the present invention, CO₃ ^2-And OH^-The synergistic combination ensures one of the keys of good selectivity of rare earth and molybdenum.

Preferably, the CO of the raw material solution₃ ^2-Can be provided by a material which can dissociate carbonate ions in aqueous solution, preferably water-soluble carbonate; further preferred is an alkali metal carbonate such as at least one of sodium carbonate and ammonia carbonate.

The research of the invention finds that under the hydrothermal leaching system, the OH needs to be accurately controlled^-And its concentration with CO₃ ^2-The ratio of (a) to (b). The hydrothermal leaching system is controlled in the range required by the invention, and leaching selectivity and recovery rate are improved.

Preferably, the concentration of OH-in the combined leaching agent solution is 2-4 mol/L.

Preferably, in the combined leaching agent solution, OH^-/CO₃ ^2-The molar ratio of (a) to (b) is 1:1 to 4: 1.

Preferably, the solid-to-liquid ratio of the rare earth-containing molybdate to the combined leaching agent solution raw material solution is 1:4(g/mL) to 1:10 (g/mL).

On the basis of the combined leaching system, a hydrothermal leaching means cooperatively matched with the temperature is also needed to improve leaching selectivity and recovery rate.

Preferably, the temperature of the hydrothermal leaching process is 100-140 ℃; more preferably 120 to 140 ℃. Researches find that the preferable temperature is beneficial to further improving the Mo leaching rate, improving the rare earth selectivity, reducing the rare earth leaching rate and improving the rare earth recovery rate.

Preferably, the hydrothermal leaching time is 1-3 h.

According to the invention, the separation selectivity of molybdenum and rare earth can be effectively improved by the combined leaching agent solution and the hydrothermal leaching process; thereby being beneficial to the efficient recovery of each follow-up element and effectively improving the recovery rate of valuable elements.

In the invention, the molybdenum is preferably recovered from the alkaline leaching solution by extraction and back extraction, and the method comprises the following steps:

contacting the alkali leaching solution with an organic phase A, extracting, and separating to obtain an extraction phase enriched with molybdenum; contacting the extraction phase enriched with molybdenum with a stripping solution A, and performing stripping to obtain a stripping solution enriched with molybdenum;

the organic phase A comprises an extracting agent A, a diluent A and a phase modifier A; the extractant A is at least one of methyl trioctyl ammonium chloride and N263 (methyl trialkyl ammonium chloride);

the diluent A is kerosene;

the phase modifier A is sec-octanol;

preferably, in the organic phase A, the proportion of the extracting agent A, the diluent A and the phase modifier A is 1-2: 5-10: 2-6.

In the process of extracting and recovering molybdenum from the alkaline leaching solution, the ratio of O/A to O/A is (0.5/1) - (2/1), the stirring speed is 600-800 r/min, the extraction time is 10-20 minutes, and the phase separation time is 10-20 minutes.

Preferably, the stripping solution a is at least one of a sodium chloride solution, a sodium hydroxide solution and ammonia water.

Preferably, the solute concentration of the stripping solution A is 1-4 mol/L, the stripping temperature is 20-50 ℃, and the stripping time is 10-60 min.

In the invention, the alkaline leaching residue is preferably subjected to acid leaching treatment to obtain acid leaching liquid enriched with rare earth.

In the acid leaching process, the concentration of acid is 4-8 mol/L. The liquid-solid ratio is 4: 1-10: 1 mL/g. The acid leaching time is 30-90 min. The acid leaching temperature is 60-90 ℃.

Preferably, the rare earth is recovered from the acid leaching solution by extraction and back extraction, and the method comprises the following steps: and (3) contacting the acid leaching solution with an organic phase B to obtain an extraction phase, and contacting the extraction phase with a back extraction solution B to obtain a back extraction solution enriched with rare earth.

The organic phase B comprises an extracting agent B, a diluent B and a phase modifier B;

wherein the extractant B is at least one of P204, P305, P507 and N1923.

The diluent B is kerosene.

The phase modifier B is sec-octanol.

Preferably, in the organic phase B, the proportion of the extracting agent B, the diluent B and the phase modifier B is 1-2: 2-10: 3-6.

In the process of extracting and recovering rare earth from acid leaching solution, the ratio of O/A is 0.5: 1-2: 1, the stirring speed is 600-800 r/min, the extraction time is 10-20 minutes, and the phase separation time is 10-20 minutes.

Preferably, the stripping solution B is hydrochloric acid with the concentration of 1-4 mol/L, the stripping temperature is 20-50 ℃, and the stripping time is 10-60 min.

The invention discloses a preferable method for recovering valuable elements from rare earth-containing molybdate tailings, which comprises the following steps:

mixing rare earth-containing molybdate tailings, a sodium hydroxide solution and a sodium carbonate solution according to a certain proportion, and stirring at a certain temperature to obtain a suspension;

step two, filtering and washing the suspension liquid obtained in the step one to obtain an alkali leaching solution and alkali leaching residues;

step three, extracting the alkaline leaching solution in the step two, standing, separating to obtain an extraction liquid and a raffinate;

step four, carrying out back extraction treatment on the extract liquor in the step three to obtain an organic phase and a water phase;

step five, drying the alkaline leaching residues in the step two, mixing the dried alkaline leaching residues with an acid solution according to a certain proportion, and stirring to obtain a suspension;

step six, filtering and washing the suspension in the step five to obtain pickle liquor and pickle slag;

and step seven, extracting the acid leaching solution obtained in the step six, standing, separating the solution to obtain an extraction liquid and a raffinate.

And step eight, carrying out back extraction treatment on the extract liquor obtained in the step seven to obtain an organic phase and a water phase.

Preferably, the roasting slag, a sodium hydroxide solution and a sodium carbonate solution are mixed according to a certain proportion in the first step, the concentration of the sodium hydroxide solution is 1-2 mol/L, the concentration of the sodium carbonate solution is 1-2 mol/L, the liquid-solid ratio is 4: 1-10: 1mL/g, the sodium hydroxide solution and the sodium carbonate solution are added in an equal volume, the stirring temperature is 100-160 ℃, the stirring speed is 30-50 r/min, the stirring time is 1-3 hours, and the equipment is a multi-reaction-tank reaction kettle.

Preferably, the filtering and washing in the second step is to filter the suspension by using a vacuum filter, and after the filtering is finished, the alkaline leaching residue is washed for 2-3 times.

Preferably, in the step three, the extraction treatment is that the extracting agent is grade A trioctyl ammonium chloride, the diluent is kerosene, the phase modifier is sec-octanol, the extraction phase ratio is O/A (0.5/1) - (2/1), the stirring speed is 600-800 r/min, the extraction time is 10-20 minutes, and the phase separation time is 10-20 minutes.

Preferably, the back extraction treatment in the fourth step is to use a sodium chloride solution as a back extractant, the concentration of the sodium chloride solution is 1-4 mol/L, the back extraction temperature is 20-50 ℃, and the back extraction time is 10-60 min.

Preferably, the alkaline leaching residue is mixed with an acid solution in the fourth step, the concentration of hydrochloric acid is 4-8 mol/L, the liquid-solid ratio is 4: 1-10: 1mL/g, the acid leaching time is 30-90 min, the acid leaching temperature is 60-90 ℃, and the equipment is a multi-reaction-tank reaction kettle.

Preferably, filtering and washing in the fifth step are to filter the suspension by using a vacuum filter, and cleaning the acid leaching residue for 2-3 times after filtering.

Preferably, in the sixth step, the P204 type extracting agent is selected as the extracting agent, the diluting agent is kerosene, the phase modifier is sec-octanol, the extracting ratio is 0.5: 1-2: 1, the stirring speed is 600-800 r/min, the extracting time is 10-20 minutes, and the phase separation time is 10-20 minutes.

Preferably, the back extraction treatment in the step eight is to use hydrochloric acid as a back extractant, the salt concentration is 1-4 mol/L, the back extraction temperature is 20-50 ℃, and the back extraction time is 10-60 min.

Compared with the prior art, the invention has the following advantages:

1. the invention fills the technical blank of effectively separating rare earth and molybdenum in rare earth molybdate materials (such as rare earth molybdate-containing minerals);

2. the invention provides a method for separating molybdenum and rare earth from rare earth molybdate material with high selectivity for the first time^-、CO₃ ^2-The process idea of hydrothermal (high pressure) leaching under the combined leaching agent is that on the basis of the innovative technical idea, OH is further used^-、CO₃ ^2-The concentration, the molar ratio, the hydrothermal temperature and other parameters are accurately controlled, so that the separation selectivity of rare earth and molybdenum is synergistically improved, and the subsequent efficient recovery of valuable elements is facilitated.

Research shows that the selectivity of the molybdenum and the rare earth obtained by hydrothermal leaching is high, for example, the separation coefficient of molybdenum and lanthanum can reach 6100, the separation coefficient of molybdenum and cerium can reach 2090, and the separation coefficient of molybdenum and neodymium can reach 1672.

Compared with the traditional ammonia leaching molybdenum calcine, the combined leaching agent takes a sodium hydroxide solution and a sodium carbonate solution as examples, and molybdate and OH in rare earth-containing molybdate are leached under the hydrothermal leaching condition^-Reacting to generate corresponding metal hydroxide precipitate, wherein the corresponding reaction equation is MMoO₄+2NaOH＝Na₂MoO₄+M(OH)₂(M is Fe, Ca, Cu, Pb, etc.).

3. On the basis of the hydrothermal leaching, the molybdenum is innovatively and selectively transferred into the leaching solution, and the rare earth components are retained in the leaching slag with high selectivity. On the basis, the invention also innovatively utilizes the extraction-back extraction process to recover and obtain molybdenum components from the leachate; the rare earth component is recovered by carrying out acid leaching on the alkaline leaching residue and combining an extraction-back extraction process.

Compared with the traditional sodium molybdate extraction process, the invention adopts the methyl trioctyl ammonium chloride as the extractant to extract the alkali leaching solution, the methyl trioctyl ammonium chloride can extract molybdate under the alkaline condition, the PH of the alkali leaching solution is only slightly adjusted during extraction, and the traditional sodium molybdate extraction process is carried out under the acidic condition, thus the use of acid is undoubtedly increased.

Compared with the traditional acid leaching rare earth process, the invention basically removes the impurity elements through alkaline leaching treatment, the traditional process is to leach the raw material containing the rare earth by acid, the rare earth elements exist in the filtrate in the form of rare earth chloride, and the impurity elements in the raw material such as iron and calcium can also enter the filtrate, so that the purity of the filtrate containing the rare earth chloride is lowered, and the extraction of the rare earth chloride is interfered.

4. The method has simple and feasible process and good effect on recovering valuable elements in the tailings containing the rare earth molybdate.

5. According to the method, the leaching rate of molybdenum can reach more than 90% through the hydrothermal leaching, the primary extraction rate reaches more than 95% by adopting the organic phase A to extract the alkaline leaching solution, and the primary stripping rate of the stripping solution A reaches 90%.

In the combined alkaline leaching process, the leaching rate of La can be as low as 0.035%; the leaching rate of Ce can be as low as 0.1%; the leaching rate of Nd can be as low as 0.15%; has good Mo and rare earth selectivity.

Acid leaching is carried out on the alkaline leaching residue, wherein the leaching rate of the rare earth element La reaches more than 80%, the leaching rate of Ce reaches more than 85%, the leaching rate of Nd reaches more than 95%, and by matching with the subsequent action of the organic phase B, the primary extraction rate of the rare earth element reaches more than 80%, and the primary back-extraction rate of the back-extraction solution B reaches 80%.

The total recovery rate of molybdenum can reach 90 percent; the total recovery rate of rare earth can reach 80%.

Drawings

FIG. 1 is a flow chart of an experiment in the present specification.

Detailed Description

The present invention will be described in detail with reference to the following specific embodiments, and it is apparent that the embodiments described are only a part of the embodiments of the present invention, rather than the whole embodiments, and all other embodiments obtained by those skilled in the art without inventive labor based on the embodiments of the present invention belong to the protection scope of the present invention.