Beneficiation method for efficiently recovering barite from heat treatment drilling waste

Abstract

The invention discloses a beneficiation method for efficiently recovering barite from heat treatment drilling waste. The beneficiation method comprises the following steps that (1) the drilling waste containing the barite is subjected to wet screening classification; (2) performing magnetic separation on the undersize product to obtain a magnetic product and a non-magnetic product; (3) carrying out primary roughing and primary concentration on the non-magnetic product to obtain a barite powder product 1; and (4) the roughing tailings are subjected to scavenging for three times, scavenged concentrates are combined and then subjected to fine selection for two times, and a barite powder product 2 is obtained. According to the method, barite in the heat treatment drilling waste is efficiently recycled by adopting a beneficiation method, two different grades of barite powder products are obtained and can serve as drilling fluid raw materials to be recycled, resource utilization of the waste is achieved, and meanwhile environmental hazards are reduced.

Description

Technical Field

[0001] The invention relates to the field of mineral processing, and in particular to a mineral processing method for efficiently recovering barite from thermally treated drilling waste. Background Art

[0002] Drilling waste is composed of various components including drilling cuttings, petroleum and drilling fluid generated during the drilling process. Among them, barite is often used as a weighting agent for drilling fluid to increase its density. my country produces a large amount of drilling waste every year. If it is not properly handled, it will cause great harm to soil, groundwater, etc. At the same time, drilling waste contains valuable components such as barite, so it is of great significance for the resource utilization of drilling waste. At present, there are solidification method, backfill method, heat treatment method, biological treatment method, etc. for the treatment of drilling waste. Among them, the heat treatment method is to heat to the distillation or cracking temperature (200-1000℃) of the oil in the drilling waste under anaerobic conditions, and then maintain this temperature until all the oil is separated. The distilled oil can be processed into products, and the oil-free solids are further treated by solidification technology. This technology is widely used in the harmless treatment of oily sludge in China.

[0003] At present, the research objects for the recovery of barite are mainly focused on untreated drilling waste, and there are few related studies on the efficient recovery of barite from heat-treated drilling waste by mineral processing methods. After high-temperature heat treatment, the physical composition and structure of drilling waste will change significantly, and the process required to recover barite is also quite different from that before treatment. Patent CN114029155A discloses a mineral processing method for recovering weighting agents in drilling fluids by gravity separation, and a combined method of classification-gravity separation-flotation is used to obtain barite concentrate products, but the recovery rate is only about 50%. Patent CN214299978U discloses a barite drilling weighting agent recovery device, which obtains barite drilling weighting agents through high-temperature calcination, oxidation-reduction, precipitation and washing operations. Under the same conditions, the product performance is better than that of ordinary barite weighting agents, but there are disadvantages of high energy consumption and complex process. Patent CN116060205A discloses a process for recovering barite from the residual solid phase of thermal desorption of drilling oil-based cuttings. A special physical purification method is used to obtain a barite product that meets the enterprise level II standard. The process uses nanobubbles for flotation, and the bubble diameter is difficult to accurately control in the actual production process. Summary of the invention

[0004] The object of the present invention is to provide a beneficiation method for efficiently recovering barite from heat-treated drilling waste. The method uses beneficiation means to comprehensively utilize the potential secondary resource of heat-treated drilling waste, which not only reduces environmental hazards, but also the two barite products obtained can be used for drilling fluid weighting agents for recycling, thereby improving resource utilization efficiency.

[0005] The present invention provides a beneficiation method for efficiently recovering barite from thermally treated drilling waste, comprising the following steps:

[0006] S1. Wet screening and classifying the drilling waste to obtain undersize products and tailings;

[0007] S2. Magnetic separation is performed on the undersize product obtained in step S1 to obtain a magnetic product and a non-magnetic product;

[0008] S3. The non-magnetic product obtained in step S2 is subjected to a roughing process to obtain a roughing concentrate and a roughing tailings;

[0009] S4. The rougher concentrate obtained in step S3 is subjected to a primary beneficiation to obtain a barite powder product 1;

[0010] S5. The rougher tailings obtained in step S3 are scavenged three times, and the scavenged concentrates obtained from the three scavengings are combined and then scavenged twice to obtain a barite powder product 2.

[0011] Furthermore, in step S1, the drilling waste components include barite, hematite, quartz, calcite, lime and the like.

[0012] Furthermore, in the wet sieving classification in step S1, the sieve hole size is 38-74 μm.

[0013] Furthermore, in step S2, the magnetic separation frame concentration is 20% to 30%, the magnetic field strength is 2000 to 4000 Gs, and the obtained magnetic separation product is used as tailings.

[0014] Furthermore, the mass concentration of mineral solid particles in the flotation slurry in all flotation processes in steps S3 to S5 is 25% to 35%.

[0015] Furthermore, the reagent system for roughing in step S3 is as follows: the pH adjuster is dilute hydrochloric acid, and the pH of the slurry is adjusted to 8-9; the dispersant is sodium carbonate, and the dosage is 300-600 g / t; the inhibitor is a combination of agents including sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 600-1200 g / t; the collector is a combination of agents including sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate: benzohydroxamic acid: coconut amine is (150-200):(15-30):1, and the dosage is 800-1000 g / t.

[0016] Further, the selection in step S4 is selection 1, specifically, an inhibitor and a collector are added in sequence; the inhibitor is a combination of agents including sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 400-800 g / t; the collector is a combination of agents including sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 200-300 g / t; the selected tailings are returned to the roughing step, and the selected concentrate is used as the barite powder product 1.

[0017] Further, step S5 includes the following steps:

[0018] The roughing tailings in step S3 are subjected to three scavengings, including scavenging one, scavenging two, and scavenging three; the dosage of the reagents in the three scavengings is the same, specifically: the inhibitor is a combination of reagents including sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 500-800 g / t; the collector is a combination of reagents including sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 200-400 g / t; the scavenging tailings obtained by scavenging one are subjected to scavenging two, and the scavenging tailings obtained by scavenging two are subjected to scavenging three, and the scavenging tailings obtained by scavenging three are subjected to tailings treatment;

[0019] The scavenged concentrates obtained from the three scavenging processes are combined for two concentrations, namely concentration 2 and concentration 3; only inhibitors are used in the reagent system of concentration 2, and the inhibitor used in concentration 2 is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 300-500g / t; blank flotation is performed in concentration 3; the concentrate obtained from concentration 3 is used as barite powder product 2.

[0020] Step S5 also includes a scavenging, which is scavenging four; scavenging four uses the tailings of the selected two as the flotation object, and only adds a collector. The collector used in the scavenging four is a combination of sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate: benzohydroxamic acid: coconut amine is (150-200): (15-30): 1, and the dosage is 100-200g / t; the scavenging concentrate obtained by scavenging four is combined with the selected tailings obtained by the selected three and returned to the selected two; the scavenging tailings obtained by scavenging four are treated as tailings.

[0021] Principle of the present invention:

[0022] The collector used in barite flotation is composed of sodium oleate, benzohydroxamic acid and coconut amine. Sodium oleate has good collecting performance. It chemically adsorbs on the surface of barite to make it hydrophobic and float. It also has foaming properties, so there is no need to add a separate foaming agent. Benzohydroxamic acid can react with Ba on the surface of barite. 2+ It forms a chelating structure, thus having strong selectivity. When used in combination with sodium oleate, it can effectively improve the phenomenon of gangue entrainment, making up for the poor selectivity of sodium oleate. Cocoamine mainly plays an emulsifying role, avoiding the formation of micelles between sodium oleate molecules in the collector, and at the same time is beneficial to the dispersion of the collector in the slurry, making its interaction with the mineral more sufficient.

[0023] The inhibitor used in barite flotation is composed of sodium silicate and tannic acid. The HSiO3- ions formed by sodium silicate in the slurry can have a good inhibitory effect on quartz and other silicate gangue minerals; tannic acid contains more hydroxyl and carboxyl groups, which can effectively inhibit gangue minerals such as calcite and hematite.

[0024] Beneficial effects of the present invention:

[0025] (1) The present invention proposes a beneficiation method for efficiently recovering barite from heat-treated drilling waste, and obtains two different grades of barite powder products through magnetic separation and flotation, both of which can be used as raw materials for drilling weighting agents, thereby achieving efficient and comprehensive utilization of this type of secondary resources and improving economic and environmental benefits;

[0026] (2) The composite collector composed of sodium oleate, benzohydroxamic acid and coconut amine used in the method of the present invention has good collecting property, selectivity and foaming property, and significantly reduces the entrainment of gangue minerals; coconut amine as an emulsifier improves the dispersibility and solubility of the collector, thereby enhancing the interaction between the collector and the target mineral;

[0027] (3) The composite inhibitor composed of sodium silicate and tannic acid used in the method of the present invention has a good selective inhibitory effect on gangue minerals such as quartz, hematite, and calcite, which is beneficial to improving the grade of barite products;

[0028] (4) The present invention uses conventional flotation equipment and reagents, and the process is simple and easy to implement in industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, they will be described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0031] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0032] The process flow chart of the present invention is as follows Figure 1 As shown, the specific steps are shown in the embodiments.

[0033] Example 1

[0034] The BaSO4 content of the drilling waste used for heat treatment in this embodiment is 69.60%, the Al2O3 content is 2.45%, and the SiO2 content is 13.46%.

[0035] Wet-screening the drilling waste with a sieve size of 38 μm to obtain an undersize product;

[0036] The under-screen product is subjected to magnetic separation, with a pulp concentration of 25% and a magnetic field strength of 3000 Gs to obtain magnetic products and non-magnetic products;

[0037] The non-magnetic product was subjected to a rough selection. The pH adjuster used was dilute hydrochloric acid, and the pH of the pulp was adjusted to 8-9; the dispersant used was sodium carbonate, and the dosage was 400g / t; the inhibitor used was composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage was 1000g / t; the collector used was composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage was 900g / t.

[0038] The rougher concentrate is subjected to a first concentration (selection 1), and the inhibitor used is composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage is 600g / t; the collector used is composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage is 200g / t. The selection 1 tailings are returned to the rougher to form a closed circuit, and the selection 1 concentrate is used as the barite powder product 1.

[0039] The roughing tailings were scavenged three times, and the inhibitor used was composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage was 600g / t; the collector used was composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage was 200g / t. The dosage of the reagents used in the three scavengings was the same.

[0040] The concentrates from scavenging 1 to scavenging 3 are combined and then subjected to two rounds of concentrating. The inhibitor used in concentrating 2 is composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage is 400g / t. The tailings of concentrating 2 are subjected to one scavenging (scavenging 4), and the collector used is composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage is 150g / t. The concentrate of scavenging 4 is combined with the tailings of concentrating 3 and returned to concentrating 2 to form a closed circuit. Concentrating 3 is blank flotation, and the concentrate is used as barite powder product 2.

[0041] After testing, the BaSO4 content in barite powder product 1 is 95.30% and the density is 4.26g / cm 3 The yield is 37.62% and the recovery rate is 51.51%, which meets the China National Petroleum Corporation corporate standard Q / SY 17008-2019 drilling fluid weighting agent barite grade I standard. The BaSO4 content in barite powder product 2 is 92.73% and the density is 4.15g / cm 3 The yield is 25.66%, the recovery rate is 34.19%, which meets the barite grade II standard. The comprehensive recovery rate of barite is 85.70%.

[0042] Example 2

[0043] The BaSO4 content of the thermally treated drilling waste used in this embodiment is 68.14%, the Al2O3 content is 3.52%, and the SiO2 content is 15.88%.

[0044] Wet-screening the drilling waste, with a sieve size of 74 μm, to obtain an undersize product;

[0045] The under-screen product is subjected to magnetic separation, with a pulp concentration of 25% and a magnetic field strength of 3000 Gs to obtain magnetic separation products and non-magnetic products;

[0046] The non-magnetic product was subjected to a rough selection. The pH adjuster used was dilute hydrochloric acid, and the pH of the pulp was adjusted to 8-9; the dispersant used was sodium carbonate, and the dosage was 400g / t; the inhibitor used was composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage was 1500g / t; the collector used was composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage was 1000g / t.

[0047] The rougher concentrate is subjected to a first concentration (selection 1), and the inhibitor used is composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage is 800g / t; the collector used is composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage is 250g / t. The selection 1 tailings are returned to the rougher to form a closed circuit, and the selection 1 concentrate is used as the barite powder product 1.

[0048] The rougher tailings were scavenged three times, and the inhibitor used was composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage was 800g / t; the collector used was composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage was 250g / t. The dosage of the reagents used in the three scavengings was the same.

[0049] The concentrates from scavenging 1 to scavenging 3 are combined and then subjected to two rounds of concentrating. The inhibitor used in concentrating 2 is composed of sodium silicate and tannic acid in a mass ratio of 10:1, and the dosage is 500g / t. The tailings of concentrating 2 are subjected to one scavenging (scavenging 4), and the collector used is composed of sodium oleate, benzohydroxamic acid, and coconut amine in a mass ratio of 160:20:1, and the dosage is 200g / t. The concentrate of scavenging 4 is combined with the tailings of concentrating 3 and returned to concentrating 2 to form a closed circuit. Concentrating 3 is blank flotation, and the concentrate is used as barite powder product 2.

[0050] After testing, the BaSO4 content in barite powder product 1 is 94.13% and the density is 4.21g / cm 3 The yield is 40.25% and the recovery rate is 55.60%, which meets the China National Petroleum Corporation corporate standard Q / SY 17008-2019 drilling fluid weighting agent barite grade I standard. The BaSO4 content in barite powder product 2 is 90.87% and the density is 4.08g / cm 3 The yield is 24.82%, the recovery rate is 33.10%, which meets the barite grade II standard. The comprehensive recovery rate of barite is 88.70%.

[0051] Comparative Example 1

[0052] Compared with Example 1, except that the collector is replaced by sodium oleate, the other steps and conditions are exactly the same as those of Example 1. That is, only sodium oleate is used as the collector, and the total amount remains unchanged.

[0053] After testing, the BaSO4 content of the obtained barite powder product 1 is 89.71% and the density is 4.05g / cm 3 The yield is 48.95%, the recovery rate is 63.09%, and it meets the China National Petroleum Corporation enterprise standard Q / SY 17008-2019 drilling fluid weighting agent barite grade II standard; the obtained barite powder product 2 has a BaSO4 content of 85.39% and a density of 3.98g / cm 3 The yield was 22.65% and the recovery rate was 27.79%, which did not meet the product standard of barite weighting agent for drilling fluid of China National Petroleum Corporation enterprise standard Q / SY 17008-2019.

[0054] Comparative Example 2

[0055] Compared with Example 1, except that the inhibitor is replaced by sodium silicate, other steps and conditions are exactly the same as those of Example 1. That is, only sodium silicate is used as the inhibitor, and the total amount remains unchanged.

[0056] After testing, the BaSO4 content of the obtained barite powder product 1 is 91.03% and the density is 4.07g / cm 3 The yield is 39.59% and the recovery rate is 51.78%, which meets the China National Petroleum Corporation corporate standard Q / SY 17008-2019 drilling fluid weighting agent barite grade II standard; the obtained barite powder product 2 has a BaSO4 content of 88.28% and a density of 4.03g / cm 3 The yield was 28.79% and the recovery rate was 36.52%, which did not meet the product standard of barite weighting agent for drilling fluid of China National Petroleum Corporation enterprise standard Q / SY 17008-2019.

Claims

1. A method for efficiently recovering barite from thermally treated drilling waste, characterized in that: The following steps are involved: S1. Wet screening and classifying the drilling waste to obtain undersize products and tailings; S2. Magnetic separation is performed on the undersize product obtained in step S1 to obtain a magnetic product and a non-magnetic product; S3. The non-magnetic product obtained in step S2 is subjected to a roughing process to obtain a roughing concentrate and a roughing tailings; S4. The rougher concentrate obtained in step S3 is subjected to a primary beneficiation to obtain a barite powder product 1; S5. The rougher tailings obtained in step S3 are scavenged three times, and the scavenged concentrates obtained from the three scavengings are combined and then scavenged twice to obtain a barite powder product 2.

2. The method for efficiently recovering barite from thermally treated drilling waste according to claim 1, characterized in that: In step S1, the drilling waste components include barite, hematite, quartz, calcite and lime.

3. The ore dressing method for efficiently recovering barite from thermally treated drilling waste according to claim 1, characterized in that: In the wet sieving classification of step S1, the sieve hole size is 38 to 74 μm.

4. The ore dressing method for efficiently recovering barite from thermally treated drilling waste according to claim 1, characterized in that: In step S2, the magnetic separation frame concentration is 20% to 30%, the magnetic field strength is 2000 to 4000 Gs, and the obtained magnetic separation product is used as tailings.

5. The ore dressing method for efficiently recovering barite from thermally treated drilling waste according to claim 1, characterized in that: The mass concentration of mineral solid particles in the flotation slurry in all flotation processes in steps S3 to S5 is 25% to 35%.

6. The ore dressing method for efficiently recovering barite from thermally treated drilling waste according to claim 1, characterized in that: The reagent system for roughing described in step S3 is as follows: the pH adjuster is dilute hydrochloric acid, and the pH of the slurry is adjusted to 8-9; the dispersant is sodium carbonate, and the dosage is 300-600 g / t; the inhibitor is a combination of agents including sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 600-1200 g / t; the collector is a combination of agents including sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate: benzohydroxamic acid: coconut amine is (150-200):(15-30):1, and the dosage is 800-1000 g / t.

7. The ore dressing method for efficiently recovering barite from thermally treated drilling waste according to claim 1, characterized in that: The selection in step S4 is selection one, specifically, an inhibitor and a collector are added in sequence; the inhibitor is a combination of agents including sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 400-800 g / t; the collector is a combination of agents including sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate: benzohydroxamic acid: coconut amine is (150-200):(15-30):1, and the dosage is 200-300 g / t; the selected tailings are returned to the roughing step, and the selected concentrate is used as the barite powder product 1.

8. The ore dressing method for efficiently recovering barite from thermally treated drilling waste according to claim 1, characterized in that: Step S5 includes the following steps: The roughing tailings in step S3 are subjected to three scavengings, including scavenging one, scavenging two, and scavenging three; the dosage of the reagents in the three scavengings is the same, specifically: the inhibitor is a combination of reagents including sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 500-800 g / t; the collector is a combination of reagents including sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate:benzohydroxamic acid:coconut amine is (150-200):(15-30):1, and the dosage is 200-400 g / t; the scavenging tailings obtained by scavenging one are subjected to scavenging two, and the scavenging tailings obtained by scavenging two are subjected to scavenging three, and the scavenging tailings obtained by scavenging three are subjected to tailings treatment; The scavenged concentrates obtained from the three scavenging processes are combined for two concentrations, namely concentration 2 and concentration 3; only inhibitors are used in the reagent system of concentration 2, and the inhibitor used in concentration 2 is a combination of sodium silicate and tannic acid, wherein the mass ratio of sodium silicate to tannic acid is (5-10):1, and the dosage is 300-500g / t; blank flotation is performed in concentration 3; the concentrate obtained from concentration 3 is used as barite powder product 2.

9. The method for efficiently recovering barite from thermally treated drilling waste according to claim 8, characterized in that: Step S5 also includes a scavenging, which is scavenging four; scavenging four uses the tailings of the selected two as the flotation object, and only adds a collector. The collector used in the scavenging four is a combination of sodium oleate, benzohydroxamic acid, and coconut amine, wherein the mass ratio of sodium oleate: benzohydroxamic acid: coconut amine is (150-200): (15-30): 1, and the dosage is 100-200g / t; the scavenging concentrate obtained by scavenging four is combined with the selected tailings obtained by the selected three and returned to the selected two; the scavenging tailings obtained by scavenging four are treated as tailings.

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