Method for synthesizing oxalate and co-producing alkyl carbonate from alkyl oxalate

The invention discloses a method for synthesizing oxalate and co-producing alkyl carbonate from alkyl oxalate, which comprises the following steps: (1) adding the alkyl oxalate and a metal compound into a container A, and fully mixing; (2) the alkyl carbonate generated by the reaction flows out from the upper part of the container A, and is condensed, rectified and purified to obtain an alkyl carbonate product; and (3) carrying out solid-liquid separation on a solid-liquid mixture flowing out from the lower part of the container A, returning a liquid-phase material to the container A for recycling, and carrying out post-processing on the separated solid material to obtain an oxalate product. In the technical field of chemical engineering, multi-product output is achieved, the technological method is simple and novel, industrialization is easy, raw materials are recycled and reutilized, economic benefits are high, and a new way is provided for comprehensive utilization industrialization ...

Novel dimmable shutter

The invention relates to a novel dimmable shutter. The novel dimmable shutter comprises a rotating shaft, a whole column of blades connected to the rotating shaft, a decorative section, a balancing weight and a draw cord, wherein at least one movable blade is arranged in the blades and is divided into three sections, namely an overturning blade section and connecting blade sections positioned on two sides of the overturning blade section, adjacent sections are connected through a connecting piece, and the movable blade and connecting piece are together inserted on a thin shaft; the balancing weight vertically moves in the decorative section; one end of the draw cord is fixed to the rotating shaft, and the other end of the draw cord is sequentially connected with all connecting pieces from top to bottom until the balancing weight. When the blades of the shutter are closed, the rotating shaft is continuously rotated, the draw cord drags a connecting piece connected with the draw cord to move ...

Walking beam balanced span and moment regulating economized oil pump and a stroke regulating device of the same

A walking beam balanced span and moment regulating oil pump having an arc, a walking beam, a support, a pitman, a base, a crank, a decelerator, a power machine, and a string device. The upper part or the lower part of the front end of a boom is articulated to the rear end of the walking beam, and between the lower part or the upper part of the boom and the rear end of the walking beam is placed a weighted arm regulator, and a weighted device is installed on the end of the boom. The walking beam balanced span and moment regulating oil pump is simple in structure, easy to operate, reliable in performance and less costly than conventional devices.

High-stability composite mercury catalyst for hydrochlorination of acetylene

The invention discloses a high-stability composite mercury catalyst for hydrochlorination of acetylene. The catalyst comprises the following components: 100 parts of active carbon serving as a carrier, 1-15 parts of mercuric chloride serving as a main catalytic component and 0.1-6 parts of auxiliary component, wherein the auxiliary component is one of chlorides of potassium, barium and lithium or a mixture of multiple of the chlorides, or one of chlorides of strontium, chromium and praseodymium or a mixture of multiple of the chlorides. According to the invention, the problems of the current mercuric chloride catalyst that the thermal stability is low, mercury in the catalyst is easy to volatilize and lose, the service life is short and the environmental pollution is serious are solved. The catalyst disclosed by the invention has the advantages of good dispersibility and high thermal stability, wherein the stability is improved by 0.1-0.5 times compared with that of the pure mercuric chloride ...

Mercury recovering and dry distillation device for waste mercury catalyst

The invention provides a mercury recovering and dry distillation device for a waste mercury catalyst. With the adoption of the mercury recovering and dry distillation device for the waste mercury catalyst, the recovery rate of mercury in the waste mercury catalyst is high, secondary pollution is small, the energy consumption is low, and operation automation is easily realized. The mercury recovering and dry distillation device for the waste mercury catalyst comprises the following connecting parts: a top cabin, furnace tubes, a bottom cabin and an electromagnetic controller, wherein the outer wall of each furnace tube is provided with a temperature measuring device, thermal insulation cottons and an electromagnetic wire are sequentially wound at the outer wall of each furnace tube, the electromagnetic controller is a single large power or small power combination body; a feeding hole and a discharge hole are formed in the top cabin, an inlet of the top cabin is connected with an auxiliary ...

Method for pretreating maleic anhydride absorption liquid

The invention discloses a maleic anhydride absorption liquid pretreatment method, which comprises three steps of filtration, steam stripping and adsorption, in the first step, solid impurities in a maleic anhydride absorption liquid are completely removed by using a filter screen, the number of filtration meshes is 20-1000, the temperature is 20-120 DEG C, and the pressure is 0.01-0.5 MPa; in the second step, volatile organic matters in the maleic anhydride absorption liquid are completely removed through steam stripping, the volume ratio of steam stripping gas to the liquid is 200-2000, the temperature of the steam stripping gas is 100-200 DEG C, and the pressure of the steam stripping gas is 0.35-0.6 MPa; in the third step, an adsorbent is adopted for adsorbing and removing non-volatile organic matter and coloring matter in the maleic anhydride absorption liquid, the liquid volume space velocity is 1-10 h <-1 >, the temperature is 100-200 DEG C, and the pressure is 0.01-1 MPa. The problems ...

Bauschinger effect evaluation method of sleeve tube used for thickened oil steam huff-and-puff thermal production well

The invention discloses a bauschinger effect evaluation method of a sleeve tube used for a thickened oil steam huff-and-puff thermal production well and belongs to the field of petroleum and gas extraction. The method includes following steps: S1: measuring an initial yield strength [sigma]0 and a tensile strength [sigma]t of a to-be-evaluated sleeve tube material; S2: obtaining a sleeve tube sample, carrying out multiple symmetrically pull-push cyclic test to obtain yield strengths [sigma]1, [sigma]2, [sigma]3, etc. of every stretching stages; S3: calculating increments [delta][sigma]1, [delta][sigma]2, [delta][sigma]3, etc. of the yield strengths after every pull-push cyclic tests and defining an average value of the increments of the yield strengths as [delta][sigma]; S4: predicting a total increment [delta][sigma]T of the yield strengths within a service life of the sleeve tube according to a formula [delta][sigma]T=A*B*[delta][sigma]; S5: determining the to-be-evaluated sleeve tube ...

Method for preparation of fodder by using coarse fiber material

Oil-containing sludge resource treatment method

The invention relates to an oil-containing sludge resource treatment method, which comprises the following steps of: flushing the oil-containing sludge by using sewage after electric air flotation, and separating out crude oil by using electric air flotation; delivering the flushed oil-containing sludge to a flow curtain type extraction tower, and performing extraction at the temperature of between 10 and 80 DEG C, wherein the volume ratio of an extraction solvent to the oily sludge is 1-15:1, the extraction solvent is a mixture of No.6 solvent oil and aromatic hydrocarbon, the boiling point of the extraction solvent is 60 to 150 DEG C, or the extraction solvent is oilfield gas condensate or petroleum ether; feeding the extraction mixed solution into a sedimentation tank, and performing natural sedimentation to separate an oil phase and an aqueous phase; delivering the oil phase to a fractionating tower to fractionate the extraction solvent and the crude oil; and washing the extracted muddy ...

Prediction method of activation energy in heavy oil combustion process

The invention provides a prediction method of activation energy in a heavy oil combustion process. The prediction method comprises the following steps of: taking model heavy oil for distilling to obtain a plurality of pseudo-components having boiling points at different temperature sections; respectively conducting the combustion experiments of the plurality of pseudo-components to respectively obtain an activation energy changing curve of each pseudo-component in the combustion process, thereby establishing a prediction model; carrying out the composition analysis of a heavy oil sample to be predicated, determining the corresponding relationships of the pseudo-components in the heavy oil sample to be predicated and a plurality of pseudo-components in the model heavy oil, and obtaining the percentage of each pseudo-component in the heavy oil sample to be predicated; utilizing the predication model, obtaining weighted average of activation energy of each pseudo-component by taking the percentage ...

Immovable string lifting-up and putting-down linear motor drive electric submersible pump and method thereof

The invention discloses an immovable string lifting-up and putting-dow linear motor drive electric submersible pump and a method thereof, and relates to the technical field of oil recovery in oil fields. When the pump is put down, an oil sucker rod is connected with a putting-down mechanism, and the jacking-proof and sealing anchoring mechanism and an oil well pump are connected and then put into a well. After sealing anchoring of a jacking-proof cam and the oil well pump and butt connection between a plunger and a linear motor rotor are accomplished, a linear motor can be started to conduct lifting. When the pump needs to be inspected, a bailing device is put down by the oil sucker rod to lift out of the jacking-proof and sealing anchoring mechanism and the oil well pump, pump inspection is conducted, and an oil pipe and the linear pump in the well do not need to be lifted upwards. The immovable string lifting-up and putting-dow linear motor drive electric submersible pump and the method ...

Display instrument

The utility model discloses a display instrument. The display instrument includes a switching power supply, a DC-DC step-down circuit, a voltage output interface, a first voltage stabilizing circuit, a second voltage stabilizing circuit, a central processing unit, an AD conversion circuit, a display screen and a communication circuit. An output end of the switching power supply is electrically connected with an input end of the DC-DC step-down circuit and the voltage output interface, an output end of the DC-DC step-down circuit is electrically connected with an input end of the first voltage stabilizing circuit and an input end of the second voltage stabilizing circuit, an output end of the first voltage stabilizing circuit is electrically connected with a power end of the central processing unit, an output end of the second voltage stabilizing circuit is electrically connected with a power end of the AD conversion circuit, and the central processing unit is electrically connected with ...

Steam quality flowmeter and its measurement method

The invention relates to metrical instrument field, specifically to a steam quality flow meter and a measuring method thereof. The steam quality flow meter widely used abroad can only be used for measuring the mass of high temperature high pressure gas. However, for superheated steam, wet saturated steam, saturated steam, water, oil and other fluids, particularly for high temperature high pressure fluid with relatively small caliber size, the measurement accuracy is low and the energy loss is high. The invention comprises an outer pipe, a power supply, a differential pressure transmitter, an intelligent indicating meter and a condenser, wherein a high-precision primary element is disposed inside the outer pipe and is a blind pipe with one end closed, and pores capable of obtaining internal and external pressure difference is provided on the surface of the blind pipe. The invention has the advantages of wide application range, low pressure loss, high precision, high reliability, wide measuring ...

Method and device for generating superheated steam from high-salt boiler feed water through stage evaporation

The invention discloses a method and a device, which are used for generating superheated steam from high-salt boiler feed water through stage evaporation, and belongs to the technical field of boiler equipment. According to the method, a boiler drum is divided into a net section and a salt section; the lower part of a salt-section cyclone is connected with the salt section to achieve discharging; the bottom end of the salt-section cyclone is connected with a salt-section down pipe, the salt-section down pipe is connected with a salt-section distribution header, the other end of a salt-section riser pipe is connected with the middle of the salt-section cyclone, a cavity body in the upper part of the salt-section cyclone is connected with a corrugated plate, the top of the salt-section cyclone is connected with a salt-section steam outlet, and the salt-section steam outlet is connected with a pipeline at one end of a super heater; the net-section distribution header is connected with a net-section ...

Method for testing thick oil horizontal well

The invention discloses a method for testing a thick oil horizontal well, which comprises the following steps: firstly, placing a cable for testing the temperature and pressure of the oil well into a steel pipe which is matched with the cable in length; secondly, coiling one end of the steel pipe on a winch which is arranged on a movable chassis and driven by a hydraulic motor to rotate, passing the other end of the steel pipe through a cable driving device, and driving the steel pipe to enter into the thermal extraction thick oil horizontal well with the cable driving device; and finally recording temperature and pressure values at gas injection and oil extraction stages of the full well section every 3 to 10 meters. The method of the invention can test the temperature, pressure and the like in the thick oil horizontal well in a production state so as to ensure the normal production of the oil well.

Rod hiding type oil pumping unit

The invention relates to a reciprocating type oil pumping unit for oil exploitation which is a rod hiding type oil pumping unit. The oil pumping unit comprises a sleeve four-way joint, an oil outlet joint, a drum shell, a drum rotary shaft, a flexible polish rod drum, a power drive device, a flexible belt type polish rod and an oil pumping rod connecting device, wherein the sleeve four-way joint is fixedly arranged on a sleeve, and the upper part of the sleeve four-way joint is fixedly provided with the oil outlet joint of which the side end is provided with an oil outlet; the lower end of the drum shell is fixedly arranged at the upper end of the oil outlet joint and kept being sealed at the connecting part; and the inner end of the drum rotary shaft is arranged in a cavity of the drum shell and fixedly connected with the flexible polish rod drum. The oil pumping unit has reasonable and compact structure and is convenient for use, the flexible polish rod drum is driven to rotate through ...

Oil-containing sludge resource treatment method

The invention relates to an oil-containing sludge resource treatment method, which comprises the following steps of: flushing the oil-containing sludge by using sewage after electric air flotation, and separating out crude oil by using electric air flotation; delivering the flushed oil-containing sludge to a flow curtain type extraction tower, and performing extraction at the temperature of between 10 and 80 DEG C, wherein the volume ratio of an extraction solvent to the oily sludge is 1-15:1, the extraction solvent is a mixture of No.6 solvent oil and aromatic hydrocarbon, the boiling point of the extraction solvent is 60 to 150 DEG C, or the extraction solvent is oilfield gas condensate or petroleum ether; feeding the extraction mixed solution into a sedimentation tank, and performing natural sedimentation to separate an oil phase and an aqueous phase; delivering the oil phase to a fractionating tower to fractionate the extraction solvent and the crude oil; and washing the extractedmuddy ...

FORAGE ADDTIVE FOR GRAIN SAVING

The said additive is suitable for forages which contain more rough celluloses. It consists of FeSO4, CuSO4, ZnSO4, MnSO4, MgS4, KI, COCl2, Na2SeO3 and carriers in a proper proportion by weight. The above-said celluloses refer to corncob, corn stalk, wheat straw, rice straw, peanut shell, etc. and the carriers, refer to wheat bran, rice chaff silkworm excrement or calcium-containing powder. The said additive can make it possible for the above materials to be converted into usable forages.

Combined cutting tool applied to nickel starting sheet preparation unit nail lugs

The invention relates to the technical field of chemical equipment, in particular to a combined cutting tool applied to nickel starting sheet preparation unit nail lugs. The combined cutting tool comprises a stamping knife and a riveting knife, wherein the stamping knife is divided into a supporting part, a connecting part and a punching part, and the riveting knife is divided into a supporting part, a connecting part, a pressing part and an edge turning part; the punching part and the edge turning part are rectangular pyramids, and an orifice is broken into two petals by an edge during punching, so that the punching resistance is reduced; for lifting lugs and starting sheets with different thicknesses and hardness, turned edges after punching are large, regular in shape and good in symmetry. The connecting parts are cuboids, so that the hole size can be amended further; the supporting parts and the pressing part are cylinders, so that the punching and edge turning stroke are restricted ...

Method for testing thick oil horizontal well

The invention discloses a method for testing a thick oil horizontal well, which comprises the following steps: firstly, placing a cable for testing the temperature and pressure of the oil well into a steel pipe which is matched with the cable in length; secondly, coiling one end of the steel pipe on a winch which is arranged on a movable chassis and driven by a hydraulic motor to rotate, passing the other end of the steel pipe through a cable driving device, and driving the steel pipe to enter into the thermal extraction thick oil horizontal well with the cable driving device; and finally recording temperature and pressure values at gas injection and oil extraction stages of the full well section every 3 to 10 meters. The method of the invention can test the temperature, pressure and the like in the thick oil horizontal well in a production state so as to ensure the normal production of the oil well.

Treatment agent for curing oilfield oily sludge and treatment method for converting oilfield oil sludge or sand into organic mud or sand

The invention relates to a treatment agent for curing oilfield oily sludge and a treatment method for converting the oilfield oil sludge or sand into organic mud or sand. The treatment agent for curing the oilfield oily sludge comprises the following raw material compositions: phosphate, humate, sulphate and fly ash. The treatment method for converting the oilfield oil sludge or sand into the organic mud or sand is implemented by the following steps: firstly, fully mixing the treatment agent for curing the oilfield oily sludge and the oilfield oily sludge in a volume ratio of between 0.01:1 and 1:1; secondly, overturning the mixture after stacking for 20 to 100 days; and flattening the mixture for one month after stacking for 20 to 100 days to obtain the sludge which is well treated and can be used for planting vegetation. The treatment method solves the problem of discharging solid waste of the oilfield oily sludge, and achieves the aim of protecting environment; and the treated oilfield ...

Solid mercury catalyst for acetylene hydrochlorination

The invention discloses a solid mercury catalyst for improving activity and stability of acetylene hydrochlorination reaction, which comprises the following components in part by weight: 100 parts of active carbon carrier, 1 to 8 parts of mercuric chloride serving as a main catalysis component and 1 to 10 parts of auxiliary components, wherein the auxiliary components A and B account for 1 to 10 parts respectively, the auxiliary component A is cobalt chloride or manganese chloride, and the auxiliary component B is potassium chloride or ammonium chloride. The solid mercury catalyst aims to solve the problems of over high mercury content of the current mercuric chloride catalyst, poor catalyst stability, over high mercury consumption in the production because the active ingredients are easy to run off, quick catalyst inactivation and serious environmental pollution. The activity and the stability of the solid mercury catalyst are improved by 5 to 50 percent compared with those of the simple ...

Intermittent pumping type energy-saving control method of pumping unit and control device as well as control circuit thereof

The invention relates to an intermittent pumping type energy-saving control method of a pumping unit and a control device as well as control circuit thereof, belonging to the technical field of intermittent pumping type energy saving of beam-pumping units. The intermittent pumping type energy-saving control device of the pumping unit is characterized by comprising a master control system module of a single chip microcomputer (SCM), a ground indicating diagram data acquiring and converting module, a power supply module and a digital quantity input and output module. The intermittent pumping type energy-saving control circuit of the pumping unit is characterized by comprising a three-phase alternating-current power supply circuit of a three-phase alternating-current motor of a beam-pumping unit and a control circuit. The invention has the advantages of reasonable and compact structure and convenient use, can obviously increase the yield of oil wells in different degrees, has very obvious ...

Treatment agent for curing oilfield oily sludge and treatment method for converting oilfield oil sludge or sand into organic mud or sand

The invention relates to a treatment agent for curing oilfield oily sludge and a treatment method for converting the oilfield oil sludge or sand into organic mud or sand. The treatment agent for curing the oilfield oily sludge comprises the following raw material compositions: phosphate, humate, sulphate and fly ash. The treatment method for converting the oilfield oil sludge or sand into the organic mud or sand is implemented by the following steps: firstly, fully mixing the treatment agent for curing the oilfield oily sludge and the oilfield oily sludge in a volume ratio of between 0.01:1 and 1:1; secondly, overturning the mixture after stacking for 20 to 100 days; and flattening the mixture for one month after stacking for 20 to 100 days to obtain the sludge which is well treated and can be used for planting vegetation. The treatment method solves the problem of discharging solid waste of the oilfield oily sludge, and achieves the aim of protecting environment; and the treated oilfield ...

Nickel starting sheet machining unit current-conducting rod feed system and work method

The invention relates to the technical field of chemical devices, in particular to a nickel starting sheet machining unit current-conducting rod feed system and a work method. A control module is electrically connected with a sensing module, a current-conducting rod stepping beam, a starting sheet feed device, a lifting lug feed device and a riveting device, the current-conducting rod stepping beam, the starting sheet feed device, the lifting lug feed device and the riveting device are controlled by the control module to work, the vacancy condition of current-conducting rods is detected through an optical distance sensor, the starting sheet feed device, the lifting lug feed device and the riveting device are controlled by the control module to stop working when the vacancy condition happens to the current-conducting rods, the current-conducting rod stepping beam is driven alone to continue to step forward once, and after the current-conducting rods are supplemented, the current-conducting ...

Application of in-situ combustion flue gas to oil deposit exploitation and system

The invention provides an application of in-situ combustion flue gas to oil deposit exploitation and a system. According to oil deposit exploitation, the flue gas generated by in-situ combustion is reinjected into an adjacent oil reservoir of the in-situ combustion to achieve gas driving of the oil reservoir. Equipment at least comprises a fireflooding oil reservoir and a steam injection oil reservoir. The flue gas down-hole reinjection system comprises a casing pipe (21), a gas injection perforating pipe (22) and an oil-extraction oil pipe (23), wherein the gas injection perforating pipe (22) and the oil-extraction oil pipe (23) are arranged in the casing pipe side by side. A one-way valve (29) is arranged at the position, opposite to the bottom of the in-situ combustion, of the gas injection perforating pipe, and a hole (210) is formed in the position, opposite to the steam injection oil reservoir, of the gas injection perforating pipe. A gas-liquid separator (28) is arranged at the position ...

Boiler for preparing too-hot steam through naturally-circulating high-salt water supply and producing method thereof

The invention discloses a boiler for preparing too-hot steam through naturally-circulating high-salt water supply and a producing method thereof, and belongs to the technical field of boiler equipment. A steam washing device is fixed in a boiler drum; the inlet of the boiler drum is connected with a high-salt softened water coal economizer by a pipeline, the inlet of the steam washing device in the boiler drum is connected with a low-salt boiler water supply coal economizer by a pipeline, and the outlet of the steam washing device is communicated with the boiler drum; the lower part of the boiler drum is communicated with a drop pipe; the lower end of the drop pipe is connected with an inlet of a distribution header; the outlet of the distribution header is connected with a rising heated pipe; the other end of the rising heated pipe is connected with a steam mixture inlet of a steam-water separator in the boiler drum; a saturated steam outlet of the steam washing device is communicated ...

Method for recovering sandy oil-containing sludge

The invention belongs to the technical field of sludge treatment of oil fields and relates to a method for recovering sandy oil-containing sludge, which comprises the following steps: fully mixing extracting solvent with the sandy oil-containing sludge of the oil fields in a volume ratio of 0.5:1 at a temperature of between 10 and 80 DEG C to allow oil to dissolve in the extracting solvent to form a structure of three separated layers; then separating an extracting solvent layer, a water layer and a silt layer from one another; and performing distillation of the separated extracting solvent layer at an atmospheric pressure or reduced pressure to acquire oil and the extracting solvent respectively. The method can effectively extract and recover crude oil in the oil-containing sludge, and silt separated out reaches national stacking standards; the solvent can be recycled, and washing water can be sewage of the oil fields and can be recycled by electroflotation without causing secondary pollution ...

Process method for refining low-grade calcium formate in process and preparing high-purity calcium-based compound based on calcium formate

The invention discloses a process method for refining process low-grade calcium formate and preparing a high-purity calcium-based compound based on calcium formate downstream. The process method comprises the following steps: drying a crude product calcium formate obtained by treating methyl formate waste liquid to remove adsorbed methylal (ML) and methyl alcohol (ME), condensing tail gas to recover ML and ME, and separating in a rectification section; mixing the solid phase with water according to a certain proportion at normal temperature, stirring and dissolving, filtering, concentrating and crystallizing filtrate, centrifugally separating, and drying to obtain food/feed-grade calcium formate, recycling mother liquor water and tail gas condensate water in the process, and using filter residues for preparing cement. High-purity calcium carbonate can be prepared by heating food/feed-grade calcium formate to 500 DEG C, high-purity calcium oxide can be prepared by heating and decomposing ...

Saliferous saturated steam preparation method and device

The invention provides a saliferous saturated steam preparation method and device. A steam outlet of a boiler and a steam outlet of a steam drum are connected with a main steam valve and are connected with a steam by-pass valve through a steam by-pass. The other end of the main steam valve is connected with one end of a branch steam valve and then is connected with a main steam pipe. The other end of the main steam pipe is connected with an inlet of a superheater. The other end of the branch steam valve is connected with a superheater inlet branch. A water inlet of the boiler and a water inlet of the steam drum are connected with the superheater inlet branch. The other end of the steam by-pass valve is connected with the other end of a superheater outlet valve. The superheater inlet branch is connected to a water supply pipeline through a tee joint. A communicating pipeline is connected between an outlet pipeline of an economizer and an outlet pipeline of the superheater. A communicating ...

System for mercury in useless mercury catalyst of high -efficient environmental protection recovery

The utility model discloses a system for mercury in useless mercury catalyst of high -efficient environmental protection recovery, include processing unit, dry unit, dust removal processing unit, resolution element, cooling unit, collector unit, tail gas processing unit in advance, processing unit, dry unit, resolution element, cooling unit, tail gas processing unit couple in proper order in advance, and dust removal processing unit couples in processing unit and dry unit in advance, and the collector unit couples in resolution element and cooling unit. Whole process does not have the water pollution produce to give birth to and discharge, and the utilization ratio of waste heat is also high, easy comprehensive utilization of sediment charcoal and retreatment after the processing, and the high -efficient recovery of the useless mercury catalyst mercury of realization, the environmental issue with useless mercury catalyst processing procedure is utilized again to the useless mercury catalyst ...

High-stability composite mercury catalyst for hydrochlorination of acetylene

The invention discloses a high-stability composite mercury catalyst for hydrochlorination of acetylene. The catalyst comprises the following components: 100 parts of active carbon serving as a carrier, 1-15 parts of mercuric chloride serving as a main catalytic component and 1-10 parts of auxiliary component, wherein the auxiliary component is one of chlorides of cobalt, manganese and gadolinium or a mixture of multiple of the chlorides, or one of chlorides of bismuth, cadmium and copper or a mixture of multiple of the chlorides. According to the invention, the problems of the current mercuric chloride catalyst that the mercury consumption during production is excessively large and the environmental pollution is serious are solved. The activity of the composite mercury catalyst disclosed by the invention is improved by 5-50% compared with that of the pure mercuric chloride catalyst, the utilization efficiency of the catalyst can be effectively improved, the production cost is lowered, and ...