CN114455871B - Sea sand purifying method - Google Patents

Abstract

The invention discloses a sea sand purifying method, which belongs to the field of sea sand purification, and comprises the following steps: s1: heating sea sand, washing and separating sand from water; the adsorption force of harmful substances on the surface of the sea sand body and the sea sand body is sufficiently reduced by heating, the sea sand is stirred and rubbed by elutriation, the harmful substances on the surface of the sea sand body fall off from the sea sand body, enter water, and the harmful substances in the water are discharged together with the water by sand-water separation. The invention can quickly and effectively remove the harmful substances such as microorganisms, algae, organic matters, inorganic salts and the like adsorbed on the surface of the sea sand, reduce the sea sand into a state of river sand before sea, ensure that various indexes of the purified sea sand can reach the same grade as the river sand, ensure that chloride ions can be reduced to 0.000-0.002%, and can be used safely as the river sand. The purified sea sand of the invention can not cause corrosion of concrete reinforcing steel bars and inferior concrete after use, and has the advantages of good durability and low cost.

Description

Sea sand purifying method

Technical Field

The invention relates to the field of sea sand purification, in particular to a sea sand purification method.

Background

Since the nineteenth century invention of concrete, river sand is the least expensive, safest and reliable fine aggregate with the best durability, and has been used for over one hundred years and the standard of formed river sand has been studied. Sea sand is Liu Yuansha, which is homologous to river sand, and is called river sand which is deposited in the sea after entering the sea after being weathered by water flow and the like.

River sand and sea sand are same in source, sand bodies have the same physical and chemical properties, but after the river sand enters the sea, the river sand is polluted by various harmful substances in the sea water, and the sea sand containing the harmful substances cannot be directly used as construction sand without purification treatment. Since the sea sand contains chloride ions and other harmful substances, the direct use of the sea sand in construction engineering causes corrosion of reinforcing steel bars and poor quality of concrete, and therefore, the sea sand needs to be purified.

The inventor researches a large number of sea sand purifying factories in coastal areas such as the south to north of China, including Shenzhen, guangdong, fujian, zhejiang, jiangsu, shandong, liaoning and the like, and the sea sand purifying factories mainly consider to remove chloride salt, mud and shells in sea sand, and according to the characteristic that the chloride salt can be quickly dissolved in water at normal temperature, and the solubility of the chloride salt in water is large (the solubility of the chloride salt at normal temperature is about 35.9 percent), the chlorine and mud removing process of mechanically washing the sea sand with fresh water is adopted. Through elutriation of fresh water, chloride ions in sea sand are dissolved in water, and then the chloride ions dissolved in the water are removed along with the discharge of wastewater through sand-water separation.

However, the conventional sea sand washing method cannot effectively remove chloride ions in the sea sand, and the sea sand washed by the conventional washing method is detected after being placed for a period of time, and the chloride ions are detected again, namely the phenomenon that the purified sea sand by the conventional washing method continuously separates out the chloride ions, so that the content of the chloride ions in the sea sand cannot reach the grade of the river sand, the chloride ions in the sea sand cannot be effectively removed, and the continuously separated chloride ions can cause corrosion of reinforcing steel bars.

The inventors have also investigated a large number of "sea sand house" works using sea sand purified by the conventional elutriation method as concrete fine aggregate, and found in investigation that these "sea sand house" works have the phenomena of deterioration in concrete strength and deterioration in addition to rust of reinforcing bars. And the concrete without steel bars made of sea sand has the same inferior phenomenon. The building mortar prepared from sea sand has obvious bad quality after years. Some engineering loose cores detect the content of chloride ions in the concrete, and the content of the chloride ions does not exceed the limit value specified by the standard, but the concrete is obviously inferior.

In combination with the practical research, the harmful substances in the sea sand are found to be other harmful substances which cause inferior concrete besides chloride ions which cause rusting of the steel bars. The traditional sea sand washing method has the phenomenon that chlorine ions are continuously separated out from the washed sea sand, so that the chlorine ions cannot be effectively removed, other harmful substances which cause poor quality of concrete on the surface of the sea sand cannot be removed, and the sea sand cannot be purified and restored to the state of the river sand before entering the sea.

Disclosure of Invention

The invention provides a sea sand purifying method, which can quickly and effectively remove harmful substances such as microorganisms, algae, organic matters, inorganic salts and the like adsorbed on the surface of sea sand, reduce the sea sand into a state of river sand before sea, and the purified sea sand can not cause corrosion of concrete reinforcing steel bars and poor quality of concrete after use, and has good durability and low cost.

The technical scheme provided by the invention is as follows:

a method of purifying sea sand, the method comprising:

s1: heating sea sand, washing and separating sand from water;

the method comprises the steps of heating to enable the adsorption force of blended sediments formed by harmful substances on the surface of the sea sand body and the sea sand body to be sufficiently reduced, stirring and rubbing sea sand by elutriation to enable the blended sediments formed by the harmful substances on the surface of the sea sand body to fall off from the sea sand body, entering water, and discharging the blended sediments entering water together with the water through sand-water separation.

Further, the heating temperature should be up to a temperature at which the adsorption force of the blended sediment formed by the harmful substances on the surface of the sea sand body and the sea sand body is reduced, and the heating time should be up to a time at which the adsorption force of the blended sediment formed by the harmful substances on the surface of the sea sand body and the sea sand body is sufficiently reduced.

Further, the heating temperature is not lower than 35 degrees.

Further, the heating time is not less than 1 minute.

Further, the step S1 includes: adding sea sand and hot water into a sand washer, and heating, washing and separating sand from water in the sand washer.

Further, the step S1 includes: adding sea sand and warm water into a sand washer, injecting water vapor into the sand washer to raise the water temperature, and heating, washing and separating sand from water in the sand washer.

Further, the step S1 includes: and heating the sea sand by a sea sand heating device, and washing the heated sea sand by a sand washer and separating sand from water.

Further, the sea sand heating device is a sea sand heat treatment tank, the sea sand heat treatment tank comprises a tank body, a sea sand feeding port is arranged at the top of the tank body, a sea sand discharging port is arranged at the bottom of the tank body, and a heat medium releasing device for releasing a heat medium into the tank body and directly contacting with the sea sand is arranged on the tank body.

Further, the heat medium releasing device is a through hole formed in the wall of the tank body, and the heat medium directly releases after entering the inside of the tank body from the outside of the tank body through the through hole.

Further, the heat medium releasing device is a heat medium guiding pipeline arranged in the tank body, a heat medium releasing hole is formed in the heat medium guiding pipeline, the heat medium guiding pipeline guides the heat medium to a specific position in the tank body, and the heat medium is released at the specific position in the tank body through the heat medium releasing hole.

Further, the heat medium guiding pipe is connected with a heat medium inlet pipe and a residual heat medium outlet pipe which extend to the outside of the tank body, and the residual heat medium discharged from the residual heat medium outlet pipe is led into the heat medium inlet pipe for recycling.

Further, an inlet plugging device and an outlet plugging device for preventing the heat medium from leaking out are respectively arranged at the sea sand feeding port and the sea sand discharging port.

Furthermore, the inlet plugging device is a screw conveyor which is arranged at the sea sand feeding port and conveys sea sand into the sea sand feeding port, and the heat medium is prevented from leaking out of the sea sand feeding port by plugging the sea sand filled in the screw conveyor.

Further, the outlet plugging device is a discharge conduit arranged at the sea sand discharge port, the discharge conduit is immersed in water, and the heat medium is prevented from leaking out of the sea sand discharge port through plugging of the water.

Further, the heat medium includes steam, hot air or hot water.

Further, the sea sand heating device is a sea sand heat treatment tank, the sea sand heat treatment tank comprises a tank body, a sea sand feeding port is arranged at the top of the tank body, a sea sand discharging port is arranged at the bottom of the tank body, and a heat exchange device for enabling a heat medium to exchange heat with sea sand indirectly in a non-contact mode is arranged in the tank body.

Further, the heat exchange device is a heat exchange pipeline positioned in the tank body, and the heat exchange pipeline is connected with a heat exchange inlet pipeline and a heat exchange outlet pipeline which extend to the outside of the tank body.

Further, the heat medium is a liquid heat medium, a gaseous heat medium or a gas-liquid two-phase heat medium.

Further, the sea sand heating device is a sea sand heat treatment tank, the sea sand heat treatment tank comprises a tank body, a sea sand feeding port is arranged at the top of the tank body, and a sea sand discharging port is arranged at the bottom of the tank body;

the tank body is provided with a heat medium releasing device which releases a heat medium into the tank body and is in direct contact with the sea sand, and the tank body is internally provided with a heat exchange device which enables the heat medium and the sea sand to indirectly exchange heat in a non-contact mode.

Further, a sea sand blanking and dispersing device is arranged in the tank body.

Further, the sea sand blanking and dispersing device comprises a plurality of layers of perforated plates, and a scraper or a vibrator is arranged on each perforated plate.

Further, a heat discharging opening is formed in the top of the tank body, and hot gas discharged from the heat discharging opening is directly led into or heated and then led into the heat medium releasing device and/or the heat exchanging device for recycling.

Further, a weight sensor is arranged on the base of the tank body, a humidity sensor, a temperature sensor and a pressure sensor are arranged in the tank body, and the feeding speed of the sea sand, the discharging speed of the sea sand, the temperature of the heat medium and the consumption of the heat medium are controlled according to the values of the weight sensor, the humidity sensor, the temperature sensor and the pressure sensor.

Further, the sea sand heating device is a tunnel microwave heater, a light wave heater, an electromagnetic wave heater or an infrared heater.

Further, before S1, the method further includes:

and carrying out raw sand matching and waste screening treatment on the sea sand.

The invention has the following beneficial effects:

according to the invention, the sea sand is heated, the adsorption force of harmful substances on the sea sand body and the sea sand body is destroyed, and the heated sea sand is elutriated, so that the substances adsorbed on the sea sand fall into water from the sea sand body, and then the harmful substances are discharged together with the water through sand-water separation.

The invention can quickly and effectively remove the harmful substances such as microorganisms, algae, organic matters, inorganic salts and the like adsorbed on the surface of the sea sand, reduce the sea sand into the state of river sand before sea, and various indexes of the purified sea sand can reach the same grade as the river sand and can be safely used as the river sand. The purified sea sand of the invention can not cause corrosion of concrete reinforcing steel bars and inferior concrete after use, and has the advantages of good durability and low cost.

Drawings

FIG. 1 is a schematic view of a first mode of an embodiment of the sea sand purification method of the present invention;

FIG. 2 is a schematic diagram of a second mode of embodiment one of the sea sand purification method of the present invention;

FIG. 3 is a schematic view of a third mode of an embodiment of the sea sand purification method of the present invention;

FIG. 4 is a schematic view of a fourth mode of the first embodiment of the sea sand purifying method of the present invention;

FIG. 5 is a schematic diagram of a third embodiment of the sea sand purification method of the present invention;

FIG. 6 is a schematic diagram of a fourth embodiment of the sea sand purification method of the present invention;

FIG. 7 is a schematic view of a sea sand heat treatment tank in the third embodiment shown in FIG. 5;

FIG. 8 is a schematic view of the upper region of the sea sand heat treatment tank shown in FIG. 7;

FIG. 9 is a schematic view of a perforated plate;

FIG. 10 is a schematic view of a first mode of the heat medium guiding pipe in the third embodiment shown in FIG. 5;

FIG. 11 is a schematic view showing the installation of the heat medium guide pipe shown in FIG. 10 in a tank;

FIG. 12 is a half cross-sectional view of FIG. 11;

FIG. 13 is a schematic view of a second mode of the heat medium guiding pipe in the third embodiment shown in FIG. 5;

FIG. 14 is a schematic view of a sea sand heat treatment tank in the fourth embodiment shown in FIG. 6;

FIG. 15 is a half cross-sectional view of FIG. 14;

FIG. 16 is a schematic view of a first mode of embodiment six of the sea sand purifying method of the present invention;

fig. 17 is a schematic diagram of a second mode of embodiment six of the sea sand purifying method of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved more apparent, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.

The inventor researches sea water and sea sand to find that: in general, sea water contains a large amount of microorganisms, algae, secretions of marine animals and plants, organic matters, mud, and a large amount of inorganic salts such as sodium chloride, potassium chloride, magnesium sulfate, calcium chloride, magnesium chloride, etc., which are mainly present in the sea water in an ionic state.

Rock weathering is carried into the sea to be piled up to form sea sand, the sea sand body is soaked in sea water, microorganisms and algae in the sea water can grow on the surface of the sea sand body, the sea sand body has stronger adsorption force, other harmful substances can be blended in the sea sand body, and blended sediments are formed on the surface of the sea sand body to wrap the sea sand body.

The blending deposition of various harmful substances on the surface of the sea sand body is the reason that the traditional sea sand elutriation method can not effectively remove chloride ions, and is also the reason that the concrete is inferior, and the concrete is analyzed as follows:

1. the chlorine salt in the sea sand can be divided into two parts according to the difficulty of cleaning, wherein one part is simply adsorbed on the outer surface of the sand body, and the chlorine salt is easy to dissolve in water and has high dissolution speed, so that the chlorine salt is easy to clean by dissolving in water quickly. The other part is chlorine salt which is difficult to clean, the chlorine salt and other harmful substances are mixed and deposited on the surface of the sea sand, and the existence of the mixed deposit on the surface of the sea sand leads to the blocking of a channel of chlorine ions in the mixed deposit and chlorine ions between the mixed deposit and a sea sand body, which are dissolved in water, the chlorine ions are slowly separated out, the chlorine ions are soaked at normal temperature, the chlorine ions are slowly separated out and dissolved in the water for a long time, and the time is up to 24-72 hours after the test.

2. Because the microorganism, the algae and the like have stronger adsorption force with the sea sand bodies, the general elutriation is difficult to remove the harmful substances (microorganism, algae and other blends), the harmful substances adsorbed on the surface of the sea sand can obstruct or reduce hydration reaction of the cementing material and the sand bodies, reduce the sufficient hydration reaction of the sand bodies and the cementing material to form stable chemical binding force, and after a period of time, the sand bodies and the cementing material are separated under the action of various factors such as thermal expansion, cold contraction, external force and the like to form gaps, so that the strength of the concrete and the mortar is gradually reduced and is inferior. The sand body and the cementing material form a gap, so that air is easy to attack to cause carbonization, and corrosion of the steel bars can be accelerated.

3. The general elutriation is difficult to remove harmful substances deposited by blending on the surface of the sea sand body, and chloride ions in the blended sediment and chloride ions between the blended sediment and the sea sand body can be continuously separated out, so that the chloride ions are continuously detected after a period of time. So that chloride ions which are continuously separated out from sea sand washed by the elutriation method after the sea sand is used on a building cause corrosion of the steel bars.

In summary, besides chloride ions which cause corrosion of the steel bars, other harmful substances which cause inferior concrete on the surface of the sea sand are contained on the surface of the sea sand body in the form of blending sediment. The existence of the blending sediment can cause that the sea sand containing harmful substances is difficult to effectively remove the harmful substances by adopting a simple elutriation method, and because the blending sediment is blocked, the phenomenon that chlorine ions are continuously separated out from the cleaned purified sea sand can occur in the common elutriation method, and the chlorine salt in the sea sand is difficult to effectively remove, so that the steel bar is corroded. Meanwhile, the blending sediment prevents the cementing material from being fully hydrated with sea sand to form chemical binding force, so that a series of inferior problems and steel bar corrosion problems of the concrete are caused, and the aging of the concrete is accelerated.

Therefore, in order to prevent corrosion of concrete reinforcing bars and deterioration of concrete, it is necessary to effectively remove a blended deposit composed of chloride ions and harmful substances in sea sand, and in the present invention, effective removal means that the content of harmful substances such as chloride ions in sea sand is less than a predetermined value, so that the properties of the purified sea sand are in the same basic state as those of river sand.

The inventor further researches and has important findings that various harmful substances in the sea sand can not generate chemical reaction with the sea sand body, and the harmful substances and the sea sand body are only physically adsorbed, so that the sea sand body can be thoroughly removed theoretically. Therefore, the blending sediment can be removed only by destroying the binding force between the blending sediment and the surface of the sea sand through a physical method, so that chloride and other harmful substances in the sea sand are effectively removed, the sea sand is reduced into a river sand state, and the sea sand can be used as a sand source safely.

Based on the findings of the inventors, an embodiment of the present invention provides a sea sand purifying method, as shown in fig. 1 to 17, comprising:

s1: heating sea sand, washing and separating sand from water;

the method comprises the steps of heating to enable the adsorption force of blended sediments formed by harmful substances on the surface of the sea sand body and the sea sand body to be sufficiently reduced, stirring and rubbing sea sand by elutriation to enable the blended sediments formed by the harmful substances on the surface of the sea sand body to fall off from the sea sand body, entering water, and discharging the blended sediments entering water together with the water through sand-water separation.

From the foregoing, it is apparent that there is a certain adsorption force between the blended deposit formed by the harmful substances on the surface of the sea sand and the sea sand body, which is caused by microorganisms, algae, organic matters, and the like. Conventional sand washing processes and machines do not effectively break this adsorption force during the elutriation, and it is therefore difficult to remove these harmful substances.

The inventor finds that substances such as microorganisms, algae, organic matters and the like which are bred and adsorbed on the surface of the sea sand body in the sea water can be quickly denatured and deactivated when the substances are heated, so that the adsorption force with the sea sand body is reduced or lost.

According to the discovery, the method for heating the sea sand is adopted, so that adsorbates such as microorganisms, algae and organic matters on the surface of the sea sand body are thermally denatured, the adsorbate with the sand body is sufficiently reduced or even lost, and after the sea sand is heated, the blended sediment on the surface of the sea sand body is simply adhered to the surface of the sea sand body, and the adsorbate before being heated does not exist.

Then adding water for washing, and simply stirring and rubbing to enable the blended sediment of the harmful substances on the sea sand body, which fully reduce the adsorption force, to leave the sand body and enter water, and inorganic salts and the like blended and mixed in the sediment enter water together.

Finally, sand-water separation is carried out, and harmful substances are discharged together with water, so that chloride ions and other harmful substances in the sea sand can be fully removed, and qualified purified sea sand is obtained.

According to the invention, the sea sand is heated, the adsorption force of harmful substances on the sea sand body and the sea sand body is destroyed, and the heated sea sand is elutriated, so that the substances adsorbed on the sea sand fall into water from the sea sand body, and then the harmful substances are discharged together with the water through sand-water separation.

The invention can quickly and effectively remove the harmful substances such as microorganisms, algae, organic matters, inorganic salts and the like adsorbed on the surface of the sea sand, reduce the sea sand into the state of river sand before sea, and various indexes of the purified sea sand can reach the same grade as the river sand and can be safely used as the river sand. The purified sea sand of the invention can not cause corrosion of concrete reinforcing steel bars and inferior concrete after use, and has the advantages of good durability and low cost.

The chloride ion content in the general sea sand raw sand is 0.15%, after the sea sand is purified by the method, the purified sea sand is sampled and detected, the chloride ion content in the sea sand can be reduced to between 0.000 and 0.002 percent, which is far smaller than the index specified in JG/T494-2016 'purified sea sand for construction and municipal administration', other harmful substances and chloride ions are effectively removed together, and the chloride ion is not separated out again after the sea sand is placed for a long time, and the purified sea sand reaches the basic state of river sand.

In the present invention, the heating temperature should be such that the adsorption force of the blended deposit formed by the harmful substances on the surface of the sea sand body and the sea sand body is reduced, for example, the heating temperature is not lower than 35 degrees; the heating time should be such that the adsorption force of the blended deposit formed by the harmful substances on the surface of the sea sand body and the sea sand body is sufficiently reduced, for example, the heating time is not less than 1 minute.

In the foregoing step S1, various embodiments of heating, washing and sand-water separation of sea sand are possible, and several specific examples are given below.

Embodiment one:

as shown in fig. 1 to 4, in this embodiment, sea sand and hot water are added to a sand washer, the sea sand is directly injected into contact with the hot water, and the sea sand is heated, elutriated, and sand-water separated in the sand washer.

The present embodiment is not limited to the specific form of the sand washer, and may be, for example, a screw sand washer 1, a bucket wheel sand washer 2, a bucket chain sand washer 3, or the like. The sand washer has the main functions of stirring and rubbing sea sand, so that harmful substances leave the sea sand body and enter water, and the sand washer can also carry out sand-water separation.

The sand washers can be used singly or in combination with a plurality of sand washers of the same type, and the sand washers are heated, elutriated and sand-water separated for a plurality of times until the content of harmful substances in the sea sand meets the requirement. And a plurality of sand washers of different types can be matched for use.

Taking a spiral sand washer as an example, as shown in fig. 1, the specific implementation manner is as follows:

1. starting a first spiral sand washer, injecting hot water, conveying sea sand into the first spiral sand washer for heating and washing, fully contacting the sea sand with the hot water in the spiral sand washer, thermally denaturing harmful substances adsorbed on the sea sand body, fully reducing the adsorption force with the sea sand body, generating friction between the sea sand and the spiral sand washer in the operation stirring process of the spiral sand washer, and removing the harmful substances from the surface of the sea sand body into water.

And (3) separating sand from water, discharging harmful substances in the water together with the water, if necessary, further dehydrating the sea sand by using a dehydration device such as a dehydration vibrating screen, and heating and washing the separated sea sand in a next spiral sand washer.

It is found that the harmful substances (microorganisms, algae, animal and plant secretions, organic matters, inorganic salts and the like) adsorbed on the surface of the sea sand can sufficiently reduce the adsorption force with the sea sand body when the sea sand is heated, and the harmful substances are separated from the surface of the sea sand body and can leave the sea sand body to enter water through proper stirring and friction. Therefore, the present embodiment devised a method of heating sea sand with hot water in a mechanical elutriation apparatus and achieving removal of harmful substances on the sea sand body by agitation friction of the mechanical elutriation apparatus.

2. The sea sand enters a second spiral sand washer, hot water is injected, harmful substances which are not removed in the first spiral sand washer are further heated, the adsorption force is sufficiently reduced, and the sea sand is further separated from the surface of the sand body and falls into the water in the stirring friction process.

And (3) separating sand from water, discharging harmful substances in the water together with the water, and enabling the separated sea sand to enter a next spiral sand washer.

3. The sea sand separated by the second spiral sand washer enters a third spiral sand washer, hot water is injected into the sea sand washer for heating and washing, and harmful substances which are not separated by the first two spiral sand washers are further separated from the surface of the sand body and enter water.

And (3) separating sand from water, discharging the harmful substances which are already in the water along with the water, and circulating according to the process until various data indexes of the purified sea sand product reach set values.

4. And conveying qualified sea sand separated by sand and water to a storage yard 5 through a conveyor 4, and leaving a factory after being inspected to be qualified.

The above description is given by using the spiral sand washer 1 only, and in practical applications, different sand washers may be used. As shown in fig. 2, a wheel bucket type sand washer 2 is adopted, as shown in fig. 3, a chain bucket type sand washer 3 is adopted, and as shown in fig. 4, a spiral sand washer 1, a wheel bucket type sand washer 2 and a chain bucket type sand washer 3 are combined.

Fig. 1-4 each illustrate three washers, but are not limited to three, two or four, or other numbers, etc. According to different sea areas where the sea sand is deposited, the cleaning difficulty degree of harmful substances in the sea sand is different; the temperature of the injected hot water is different, and the reduction degree of the adsorption force of harmful substances and sand bodies is different; the number of channels of the sand washer and the number of channels for injecting hot water are designed according to the difference of factors such as different stirring friction effects of the sand washer. When the harmful substances are not completely removed, the content of the harmful substances is reduced by each sand washer, so the number of sand washers is selected until the state of reducing sea sand into river sand before sea is reached, and various indexes reach set values.

The invention does not limit that each sand washer needs to be filled with hot water, and can select part of sand washers to be filled with hot water according to the situation, part of sand washers to be filled with hot water or part of sand washers to use recycled water, wherein the recycled water refers to that the wastewater of the next sand washer is introduced into the previous sand washer to be used.

The method is simple in process, suitable for industrial continuous production, and particularly, the product index of the existing sea sand purification chemical factory can not meet the requirement, the original equipment process can be modified, and the original normal-temperature water is changed into hot water, so that qualified purified sea sand can be produced.

Embodiment two:

the present embodiment has the same structure as the first embodiment, except that: in the embodiment, sea sand and warm water are added into a sand washer, water vapor is injected into the sand washer to raise the water temperature, and the sea sand is heated, elutriated and sand-water separated in the sand washer.

In this embodiment, the same effect as in the embodiment can be obtained by injecting the water with the hot water and then injecting the steam to raise the water temperature.

Embodiment III:

the present embodiment is different from the first embodiment and the second embodiment in that: while the first and second embodiments simultaneously heat and wash sea sand in the sand washer, the heating and washing of the present embodiment are not simultaneously performed, the sea sand is first heated by the sea sand heating device, and then the heated sea sand is washed and sand-water separated by the sand washer.

As shown in fig. 5 and 7-13, the sea sand heating device in this embodiment is a sea sand heat treatment tank 6, the sea sand heat treatment tank 6 includes a tank body 61, a sea sand inlet 62 is provided at the top of the tank body 61, a sea sand outlet 63 is provided at the bottom of the tank body 61, and a heat medium releasing device for releasing a heat medium into the tank body 61 and directly contacting the sea sand is provided on the tank body 61.

Sea sand enters the tank body 61 through the sea sand feed opening 62, and a heat medium is released in the tank body 61 through a heat medium releasing device, is in direct contact with the sea sand, and directly heats the sea sand, wherein the heat medium is steam, hot air or hot water. When the sea sand is heated up to a certain temperature, the adsorption force of the harmful substances on the surface of the sand body is rapidly and fully reduced, the sea sand after heat treatment is discharged from a sea sand discharge port 63, enters a sand washer for washing, and is separated by sand and water, and the harmful substances are discharged together with water, so that qualified purified sea sand is obtained.

The sea sand heat treatment tank 6 is made of steel, and fig. 7 is only illustrative, and the invention is not limited to the shape of fig. 7, and can be made into various shapes according to the requirements, and the sea sand heat treatment tank 6 is reasonably designed according to the purification production yield, the properties of the heat medium, the temperature of the heat medium and other indexes.

The heat medium is introduced into the can 61 through an external pipe and then released, and there are various ways in which the heat medium is released in the can 61.

1. The heat medium releasing means is a through hole (not shown) formed in the wall of the tank body, and the heat medium is directly released from the outside of the tank body 61 through the through hole into the inside of the tank body 61.

The through-hole is preferably provided at the middle or upper portion of the can 61, and the heat medium is directly released at the middle or upper portion of the can 61 after entering the can 61, so that the heat medium fills the can 61.

2. There may be a layer of sea sand deposited in the lower part of the tank 61, which may be unevenly heated if the heat medium is directly released in the lower part of the tank 61.

It is thus possible to provide the heat medium releasing means as a heat medium guiding pipe 64 located in the tank 61, the heat medium guiding pipe 64 being provided with heat medium releasing holes 65, the heat medium guiding pipe 64 guiding the heat medium to a specific position in the tank 61 and releasing the heat medium at the specific position in the tank 61 through the heat medium releasing holes 65.

The heat medium guiding pipes 64 guide the heat medium to various positions in the tank 61, so that the heat medium is released more uniformly, and the sea sand in the tank is heated uniformly.

The arrangement of the heat medium guide pipes 64 is shown in fig. 10 to 13, and fig. 10 to 12 are examples, and the heat medium guide pipes 64 are provided with heat medium release holes 65 at intervals of vertical sections, and the heat medium is ejected from the heat medium release holes 65 to contact with sea sand, thereby achieving the purpose of heating the sea sand. Fig. 13 shows another example in which the heat medium guide pipe 64 is provided in a spiral configuration, and the heat medium guide pipe 64 is provided with small openings as heat medium release holes 65, and the heat medium is uniformly discharged, thereby achieving the effect of uniformly heating up the sea sand as a whole.

The number and size of the heat medium release holes 65 in the heat medium guide pipe 64 are comprehensively calculated according to the sea sand treatment amount, the temperature of the heat medium and the capacity of the tank body, and reasonable process parameters are selected.

The heat medium guide pipe 64 is connected with a heat medium inlet pipe 66 and a residual heat medium outlet pipe 67 extending to the outside of the tank 61.

The unreleased heat medium in the heat medium guide pipe 64 is discharged from the residual heat medium outlet pipe 67, and is reintroduced into the heat medium inlet pipe for reuse when the temperature of the discharged residual heat medium is still available.

Since the heat medium is directly released in the tank 61, it is necessary to provide an inlet shutoff device 68 and an outlet shutoff device 69 for preventing the heat medium from leaking out at the sea sand inlet 62 and the sea sand outlet 63 of the tank 61, respectively.

One implementation of the inlet blocking device 68 is: the inlet plugging device 68 is a screw conveyor which is arranged at the sea sand inlet 62 and conveys sea sand into the sea sand inlet, the sea sand enters a hopper of the screw conveyor, the sea sand is pushed to the sea sand inlet 62 by a screw reamer of the screw conveyor, a sea sand filling section is arranged between an inlet and an outlet of the screw conveyor, sea sand is filled in the filling section, and the heat medium is prevented from leaking out of the sea sand inlet 62 by plugging the sea sand filled in the screw conveyor.

The screw conveyor is provided with a rotating speed automatic speed regulating system, and the screw rotating speed can be automatically regulated through the change of the material metering value of the hopper of the screw conveyor, so that the phenomenon that the filling section lacks sea sand filling due to the fact that the feeding is smaller than the discharging of the screw conveyor is prevented.

One implementation of the outlet plugging device 69 is: the outlet plugging device 69 is a discharge conduit arranged at the sea sand discharge port 63, the sea sand after heat treatment is discharged to the sea sand discharge port 63, the sea sand is guided into the sand washer through the discharge conduit, the discharge conduit is immersed in water, and the heat medium is prevented from leaking out of the sea sand discharge port 63 through plugging of water.

A sea sand blanking dispersion device may also be provided within the tank 61, and in one example, the sea sand blanking dispersion device includes a perforated plate 70 as shown in fig. 9, with a scraper or vibrator mounted on the perforated plate 70. The perforated plate 70 may be provided in a single layer or in multiple layers, as shown in fig. 7.

Sea sand enters the perforated plate 70 from the sea sand feed opening 62, is scattered and falls downwards from the orifice of the perforated plate 70, so that the sea sand is prevented from falling in a concentrated manner, the dispersed and falling sea sand meets with the heat medium in the falling stage, the heat exchange is carried out, the temperature is raised, the sea sand falls to the lower part of the tank body 61 to form a stacking layer, the sea sand is further heated by the direct heating of the heat medium released by the heat medium release holes 65 on the lower heat medium guide pipeline 64, the sea sand starts to fall from entering the tank body 61, and the sea sand is stacked until the whole discharging process is in the temperature raising process. When the sea sand reaches the sea sand discharge port 63, the set highest temperature is reached, at this time, the adsorption force of harmful substances on the surface of the sea sand and sand bodies is sufficiently reduced, and the sea sand enters the sand washer through the blanking conduit.

The top of the tank body 61 is provided with a heat discharging opening 71, hot air rising to the top of the tank body 61 is intensively led out of the tank body 61 through the heat discharging opening 71, and when the temperature of the led out hot air is higher, the hot air can be led into the heat medium releasing device for repeated use, or heated by an external heater and then led into the heat medium releasing device for repeated use.

When the guided hot gas is not guided back to the tank 61 for use, the guided hot gas can be discharged into water of an external water tank to heat the cleaning water of the sand washer.

A weight sensor is arranged on the base of the tank body 61, a humidity sensor, a temperature sensor and a pressure sensor are arranged in the tank body 61, and the feeding speed of the sea sand, the discharging speed of the sea sand, the temperature of the heat medium and the consumption of the heat medium are controlled according to the values of the weight sensor, the humidity sensor, the temperature sensor and the pressure sensor.

The weight sensor displays the total weight of the tank 61 and the sea sand stock in real time, the feeding and discharging speed of the sea sand is automatically adjusted according to the set weight change of the tank, and when the discharging is kept unchanged and the total weight of the tank reaches a certain value, the sand feeding amount is increased or the sand discharging amount is reduced, and vice versa.

The temperature sensor mainly detects the temperature of the piled sea sand at the bottom of the tank body 61 and the temperature of the gaseous space in the upper tank body 61, sets the pressure and the temperature at all positions to form an automatic control system, automatically adjusts the sand inlet and outlet quantity, the sea sand outlet temperature, the heat medium inlet temperature and the pressure, and the tank pressure, forms an automatic adjusting system through software, and can be manually adjusted, so that harmful substances adsorbed on the sea sand surface can be thoroughly and effectively removed through the purifying system, and meanwhile, a heat source is saved, and the reasonable and effective effects are achieved.

The advantages of this embodiment are as follows:

1. the heat treatment of the sea sand is realized in the tank body, and the heat medium is not overflowed, so that the method is environment-friendly and safe.

2. The heat medium used is wider than those of the first and second embodiments, and hot air, steam, hot water, and the like can be used.

3. The temperature range of the heat medium is wide, and particularly, a high-temperature heat medium can be used.

4. The heat medium can be reused, the heat energy loss is less, and the utilization rate is high.

5. The sea sand can be cleaned by normal-temperature water after being led out from the material guiding pipe at the bottom of the tank body after being heated in the tank body, and the elutriation equipment is simpler.

6. The waste hot water, waste steam and waste hot gas are discharged around the sea sand purifying plant, so that the sea sand purifying plant can be fully utilized, and is environment-friendly and energy-saving.

Embodiment four:

as shown in fig. 6, 14 and 15, the sea sand heat treatment tank 8 is adopted in the present embodiment, the sea sand heat treatment tank 8 includes a tank body 81, a sea sand feeding port 82 is provided at the top of the tank body 81, a sea sand discharging port 83 is provided at the bottom of the tank body 81, and a heat exchange device 84 for indirectly exchanging heat between a heat medium and sea sand in a non-contact manner is provided in the tank body 81.

In this embodiment, although the sea sand heat treatment tank is used as in the third embodiment, the third embodiment is to directly heat the sea sand by directly contacting the sea sand with the heat medium in the tank 61. The heat medium of the present embodiment is not released in the tank 81, but indirectly exchanges heat with sea sand through the heat exchanging device 84 without contact.

The present embodiment has the following advantages in addition to the advantages of the third embodiment:

the non-contact indirect heat exchange is adopted, so that the usable heat medium is wider than the three-phase heat exchange in the embodiment, and can be, for example, hot water, heat conducting oil or other liquid heat mediums, hot air, harmful hot waste gas which is not suitable for being contacted with sea sand or other gaseous heat mediums, water vapor or other gas-liquid two-phase heat mediums.

Meanwhile, the temperature and pressure of the heat medium may be higher, and a heat medium heater may be provided outside the tank 81, and the heat medium may be reused by heating.

Since the heat medium is not released in the tank 81, the pressure in the tank 81 is low, the requirements on the sealing performance of the tank for feeding and discharging are low, and the inlet plugging device and the outlet plugging device in the third embodiment can be omitted.

The heat exchange device 84 may be a heat exchange pipe located inside the tank 81, and the heat exchange pipe may be various shapes such as a round pipe, a square pipe, an elliptical pipe, a flat pipe, etc. The heat medium passes through the pipeline, heat is transferred to the sea sand through the pipeline wall, and the heat medium is not in direct contact with the sea sand. The sea sand is input into a tank body 81, the sea sand is contacted with the wall of a heat medium pipe in the tank body 81, the sea sand is heated up when meeting heat, when the temperature reaches a certain value, the adsorption force of harmful substances on the surface of the sand body is sufficiently reduced, the sea sand after heat treatment is discharged from a sea sand discharge port 83, enters a elutriation device for elutriation, the sand and the water are separated, and the harmful substances are discharged together with water, so that qualified purified sea sand is obtained.

The heat exchange pipe 84 is connected with a heat exchange inlet pipe 85 and a heat exchange outlet pipe 86 extending to the outside of the tank 81.

Similar to the third embodiment, the sea sand heat treatment tank 8 of the present embodiment may further include a sea sand blanking dispersing device, a heat discharging opening, a weight sensor, a humidity sensor, a temperature sensor, a pressure sensor, and the like, and the description of the embodiment is specifically referred to, and will not be repeated in the present embodiment.

Fifth embodiment:

in the embodiment, the third embodiment and the fourth embodiment are combined and used, and the heat medium releasing device and the heat exchanging device are arranged at the same time, so that the direct contact heating and the indirect heat exchanging are combined and used.

Example six:

as shown in fig. 16 and 17, in this embodiment, a tunnel microwave heater 10 is provided, the sea sand containing water is input into the inlet of the tunnel microwave heater 10, the tunnel microwave heater 10 conveys the sea sand to the outlet at a certain speed, the tunnel microwave heater 10 heats the sea sand containing water in the process of passing through the tunnel microwave heater 10, when the temperature and the time set are reached, the sea sand is discharged from the outlet and enters the sand washer 3 for washing, sand-water separation is performed, and harmful substances are discharged together with water, so that qualified purified sea sand is obtained.

According to the content of harmful substances in the sea sand, different technological processes are set, for example: when the sea sand has high mud content, one or more sand washers 3 can be used for washing and removing mud at normal temperature, and the sea sand is dehydrated by a dehydrator and then enters a tunnel microwave heater for microwave heating treatment, as shown in figure 17. The sea sand is dehydrated before entering the tunnel microwave heater so as to prevent the water content from being too high and reduce the microwave energy consumption.

Embodiment seven:

in the embodiment, the sea sand is heated by light waves, or is heated by electromagnetic waves, or is heated by infrared rays, the heated sea sand is elutriated by a sand washer, sand-water separation is carried out, and harmful substances are discharged together with water, so that qualified purified sea sand is obtained.

In the present invention, before S1 is performed, the method further comprises: and (5) carrying out raw sand matching and waste screening treatment on the sea sand.

After the sea sand raw sand is detected, sand is matched according to the requirement, the matched sea sand enters a waste screening machine 9, the sea sand is screened, and coarse particles, such as mud blocks, shells and the like, in the sea sand are screened out through the waste screening machine, wherein the coarse particles are larger than 5 mm.

The waste screening machine is provided with a screen, and is used for screening out large-particle substances such as mud blocks, shells, coarse particles and the like in the sea sand, and the part smaller than the screen hole size falls from the screen to obtain the sea sand smaller than the screen hole diameter part. In the screening process, because water is added and the screening machine is stirred, the mud in the sea sand is accelerated to be dissolved in the water under the action of vibration and friction, and a large amount of mud is discharged together with the water after the sand-water separation.

While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.

Claims (14)

1. A method of purifying sea sand, the method comprising:

s1: heating sea sand, washing and separating sand from water;

the method comprises the steps of heating to enable the adsorption force of blended sediments formed by harmful substances on the surface of the sea sand body and the sea sand body to be sufficiently reduced, stirring and rubbing sea sand by elutriation to enable the blended sediments formed by the harmful substances on the surface of the sea sand body to fall off from the sea sand body, entering water, and discharging the blended sediments entering water together with the water through sand-water separation;

the S1 comprises the following steps: heating the sea sand by a sea sand heating device, and washing and separating sand from water by a sand washer;

the sea sand heating device is a sea sand heat treatment tank, the sea sand heat treatment tank comprises a tank body, a sea sand feeding port is arranged at the top of the tank body, a sea sand discharging port is arranged at the bottom of the tank body, and a heat medium releasing device for releasing a heat medium into the tank body and directly contacting with sea sand is arranged on the tank body;

the heat medium releasing device is a heat medium guiding pipeline arranged in the tank body, a heat medium releasing hole is formed in the heat medium guiding pipeline, the heat medium guiding pipeline guides the heat medium to a specific position in the tank body, and releases the heat medium at the specific position in the tank body through the heat medium releasing hole;

the vertical sections of the heat medium guide pipeline are provided with heat medium release holes at certain intervals, or the heat medium guide pipeline is arranged in a spiral mode, and small openings are formed in the heat medium guide pipeline and serve as the heat medium release holes.

2. The method for purifying sea sand according to claim 1, wherein the heating is performed at a temperature at which the adsorption force of the mixed deposit formed by the harmful substance on the surface of the sea sand body and the sea sand body is reduced, and for a time at which the adsorption force of the mixed deposit formed by the harmful substance on the surface of the sea sand body and the sea sand body is sufficiently reduced.

3. A sea sand purifying method according to claim 2, wherein the heating temperature is not lower than 35 degrees.

4. A sea sand purifying method according to claim 2, wherein the heating time is not less than 1 minute.

5. A sea sand purifying method according to claim 1, wherein the heat medium guiding pipe is connected with a heat medium inlet pipe extending to the outside of the tank body and a residual heat medium outlet pipe, and the residual heat medium discharged from the residual heat medium outlet pipe is guided into the heat medium inlet pipe for reuse.

6. The method according to claim 1, wherein the sea sand inlet and outlet are provided with an inlet blocking device and an outlet blocking device, respectively, for preventing the leakage of the heat medium.

7. The method according to claim 6, wherein the inlet blocking device is a screw conveyor which is provided at the sea sand inlet and conveys sea sand into the sea sand inlet, and the heat medium is prevented from leaking out of the sea sand inlet by blocking the sea sand filled in the screw conveyor.

8. The method according to claim 6, wherein the outlet shutoff device is a discharge conduit provided at the sea sand discharge port, the discharge conduit is immersed in water, and the leakage of the heat medium at the sea sand discharge port is prevented by shutoff of water.

9. The method of purifying sea sand according to claim 1, wherein the heat medium comprises steam, hot air or hot water.

10. The method for purifying sea sand according to any one of claims 1 to 9, wherein a sea sand blanking and dispersing device is arranged in the tank body.

11. A method of purifying sea sand according to claim 10, wherein the sea sand blanking dispersion device comprises a plurality of layers of perforated plates on which scrapers or vibrators are mounted.

12. The method for purifying sea sand according to any one of claims 1 to 9, wherein a heat discharging opening is formed at the top of the tank body, and hot air discharged from the heat discharging opening is directly introduced or heated and then introduced into the heat medium releasing device for recycling.

13. The sea sand purifying method according to any one of claims 1 to 9, wherein a weight sensor is provided on the base of the tank body, a humidity sensor, a temperature sensor and a pressure sensor are provided in the tank body, and the feeding speed of the sea sand, the discharging speed of the sea sand, the temperature of the heat medium and the amount of the heat medium are controlled according to the values of the weight sensor, the humidity sensor, the temperature sensor and the pressure sensor.

14. The sea sand purification method of claim 1, wherein S1 is preceded by:

and carrying out raw sand matching and waste screening treatment on the sea sand.