stayMineral classificationMedium,Platinum groupElement minerals belong to natural platinum subgroup, includingiridium(Ir)、rhodium(Rh)、palladium(Pd) andplatinum(Pt), etc.They exist widely among each otherIsomorphismReplacement phenomenon, thus forming a series of isomorphismMixed crystalThe metals smelted by platinum group element minerals include palladium (Pd), rhodium (Rh), iridium (Ir), platinum (Pt), etc.
Platinum group metals, also known as platinum group elements.includeruthenium（Ru）、rhodium（Rh）、palladium（Pd）、Osmium（Os）、iridium（Ir）、platinum(Pt) Six kindsmetallic element, onperiodic table of ele mentsIt belongs to the 5th and 6th cycle.This family element is in theGemologyAmong them, palladium jewelry, a new favorite of white precious metals, is an international fashionFashion jewelryPlatinumPalladium belongs to platinum groupReserveThe smallest two minerals have similar metallurgical properties. They are also rare and have similar uses, so they often interact in various applicationssuccedaneum。
Platinum group metals
Platinum group metals are famous for their particularly valuable properties and rare resources;Together with gold and silver, it is called "precious metal".But its discovery and utilization is much later than that of gold and silver.GoldSilver AccessoriesIt has been found in tombs before the era of mankind, and the understanding and utilization of platinum group metals by mankind is only two hundred years old.Among them, platinum was first discovered by Jullo in 1735, and other elements were not known until the 19th century. For example, palladium was discovered by Jullo in 1803WollastonRuthenium was discovered by K. Claus in 1845.Although they were discovered late, they soon learned that they had some valuable functions, and were widely used inmodern industryAnd cutting-edge technology.Therefore, it is called "modern precious metal".It is reported that from 4000 BC to the end of the 19th century, the global cumulative gold production was 29000 tons, and the world average annual gold production in the 19th century was 123 tons;From 1973 to 1980, the world's average annual gold production reached 1375 tons.The world output of platinum group metals has exceeded 100t since 1969, and doubled to 200t at the end of 1980s（Zhang Wenpu, 1997), with an annual output of nearly 300t in the early 1990s.From these data, it is not difficult to understand the deep meaning of "precious metals" and "modern precious metals": both are rare and valuable, and platinum group elements, although their absolute quantity is less than gold and silver, their development speed deeply reflects the meaning of "modern".
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Platinum group metals
South AmericaThe Indians ofplatinum。When the Spanish arrived in South America, they saidNatural platinumIt is "platinum".The first person who made Europeans know "Little Silver" was the Spaniard De Uloa.Hereafter, platinum is named as Platinum with reference to Platina.In 1741, C. Wood brought "Little Silver" to Europe, which aroused the interest of scientists.In 1803, W.H. Wollaston, an Englishman, established a process for purifying platinum. At the same time, he separated two new elements, palladium and rhodium, from the aqua regia solution of platinum.The former is based onMYTHOSinGoddess of WisdomPallas is named palladium;The latter because of itssalthaveroseRed, named rhodium after the Greek word rhodon (rose).In 1804, British S. Tennant discovered osmium and iridium from the aqua regia insoluble substance of natural platinum.Because osmium tetraoxide has strongvolatilityIt also has a pungent taste similar to chlorine. Iridium salts have various colors, and are named osmium and iridium respectively after the Greek words osme (smell) and iris (rainbow).Russian in 1844Claus (κ. κ лаус) found rutheniumLatinRuthenia (russia) is named ruthenium.
When an old manHigh qualityWhen a star diesSupernova explosionAt this time, the original light nucleus will be combined intoHeavy nucleusThe heavy metals will also form, and the heavy nuclei will stay in the surrounding space, and some will come to the earth.
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characteristic
Platinum group metals
Platinum group metals not only have similar physical and chemical properties, but also have their own characteristics.Their common characteristics are:Except that osmium is bluish gray[3]The ruthenium is steel gray, and the rest are silver white;High melting point, high strength, stable electrothermal performance and resistanceelectric sparkHigh erosion resistance, excellent corrosion resistance, strong high-temperature oxidation resistancecatalytic activityGood.Their characteristics determine different uses.For example, platinum has good plasticity and stable resistanceResistance temperature coefficient, can be forged into platinum wire, platinum foil, etc;It does not combine directly with oxygen, is not eroded by acid and alkali, and is only soluble in hotAqua regiaMedium;Palladium is soluble inConcentrated nitric acidIt can absorb 350~850 times of hydrogen at room temperature.Rhodium and iridium are insoluble in aqua regia and can be fused withsodium hydroxideAnd reacting with sodium peroxide to generate compounds dissolved in acid;Osmium and ruthenium are insoluble in aqua regia, but easily oxidized intoTetraoxide。Their main physical and mechanical properties are shown in Table 3.17.1.
Main physical properties
Platinum group metals
Platinum group metals except osmiumBluish greyAll other metals are silver white.Most PGMs can absorb gases, especially hydrogen.palladiumHydrogen absorptionIt has the strongest capacity. One volume of palladium can absorb 900~2800 volumes of hydrogen at room temperature.When heated to 100 ℃ under vacuum, the dissolved hydrogen is completely released.Palladium has the characteristics of hydrogen absorption and permeation: a certain volume of palladium canAbsorption ratioIt is 900 or even 2800 times larger than hydrogen (seeHydrogen storage material）。Platinum has a strong ability to absorb oxygen. One volume of platinum can absorb 70 volumes ofoxygen。When the particle size is very fine, such as platinum black, palladium black or colloidal, the adsorption capacity is stronger, so they have good catalytic properties.Pure platinum and palladium have goodDuctility, withoutIntermediate annealingCold plasticity ofDeformationIt can reach more than 90% and can be processed into micron sized filaments and foils.Rhodium and iridium have good high temperature strength, but coldPlastic processingSlightly poor performance.Osmium and ruthenium have high hardness but poor machinabilityPowder metallurgy methodThe ruthenium metal produced can only carry out a small amount of plastic processing at 1150~1500 ℃, while osmium can hardly carry out plastic processing even at high temperature.
Main chemical properties
Platinum group metals are typical precious metalschemical stabilityEspecially high, with good corrosion resistance and oxidation resistance.They can resist common acids andChemical ReagentsPlatinum does not react with ordinary acid, but can be slowly dissolved in aqua regiaChloroplatinic acid（HtwoPtClsix）。Palladium is more active in the platinum group, and its corrosion resistance to acid is slightly poor. It can quickly dissolve in nitric acid.Iridium, rhodium and ruthenium can resist the attack of single acid and chemical reagent, and even aqua regia is difficult to dissolve them.
Platinum and rhodiumOxidation resistanceVery good, it can keep luster in the air for a long time without being oxidized.At high temperature, platinum and rhodium react with oxygen to form volatile oxides, increasing its evaporation rate.Powdered iridium is oxidized in air or oxygen at 600 ℃ to form a layer of iridium oxide (IrOtwo）Film.This oxide decomposes when the temperature is higher than 1100 ℃, restoring the original luster of the metal.Iridium is the onlyOxidizing atmosphereMetal used to 2300 ℃ without serious loss.Ruthenium and osmium are easily oxidized. At room temperature, the surface of osmium is blueOxide film（OsOtwo）。Osmium tetroxide（OsOfour）AndRuthenium tetroxide（RuOfour）They are volatile toxic compounds that can irritate mucous membranes and damage skin.
Platinum group metals are transition metals with multiple valence. Their stable valence is ruthenium+3, rhodium+3, palladium+2,+4, osmium+3,+4, iridium+3,+4, platinum+2,+4.They all have a strong tendency to form complexes, the most commoncoordination number4 and 6.
Platinum has excellent thermoelectric stability, high temperature oxidation resistance and high temperature corrosion resistance.Palladium can absorb hydrogen 2800 times larger than its volume, and hydrogen can pass freely in palladium.Iridium and rhodium can resist the corrosion of various oxidants and have goodMechanical properties。Ruthenium can combine with ammonia, but does not react chemically, similar to the unique properties of some bacteria.Osmium is very brittle and hard, volumeModulus of elasticitymaximum.Osmium and ruthenium are easily oxidized, and their oxides are irritant and toxic.
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More than 200 kinds of PGE minerals have been found.It can be divided into 4 categories:
Platinum, palladium, iridium, osmium, etc., and bismuth, tellurium, selenium, antimony, etc. are in metal bond or have equivalent metal bond componentsCovalentBonded compounds;
See Table 3.17.2 for the main minerals of platinum group elements and their compositions.Industrial mineralsMainlyArsenoplatite, natural platinum, equiaxed bismuth tellurium palladium ore, tellurium palladium ore, arsenic platinum osmium ore, tellurium palladium iridium ore and bismuth tellurium palladium oreNickel ore。Arsenic platinum ore and equiaxed bismuth tellurium palladium ore are mostly found in primary platinum deposits, while natural platinum is mostly found in placer platinum ores.Precious and rare metalsPrecious metals andRare metalsThe general name of.Because gold and silver arePeople's Bank of ChinaFranchise,Material departmentThe precious metals operated are mainly platinum group elements, while selenium, tellurium and arsenic belong toscattered element, commonly referred to asSemimetal。
Platinum: platinum is a silver white metal, with a melting point of 1769 degrees and a density of 21.45g/cmthree, mainly used in electrical, instrument, chemical industry, decoration and productionPrecision alloyEtc.
Rhodium: Rhodium is a silver white metal with a melting point of 1964 degrees and a density of 12.45g/cmthree, YesBrittle metal。Electrical, instrumentationSuperalloyAnd precision alloy.
Iridium: Iridium is a silver gray metal with a melting point of 2443 degrees, which is the highest among precious metals.The density is 22.4g/cmthreeIs the second densest metal.It is a brittle metal with stable chemical properties, acid and alkali corrosion resistance and high hardness.It is used in electrical, chemical, instrumentation, light industry and other aspects to prepare precision alloys.
Osmium: Osmium is a gray blue metal, with a melting point of 3033 degrees and a density of 22.48g/cmthree, is the most dense metal.High melting point metal, brittle.Mainly used for electrical, instrumentationchemical industryAnd alloys.
Ruthenium: Ruthenium is a silver white metal, with a melting point of 2334 degrees and a density of 12.37g/mthree。It is used in electrical, instrument, chemical industry, high temperature alloy and precision alloy.
Gallium: liquid gallium is silver white metal, solid gallium is blue crystal metal, soft texture, melting point is 29.8 degrees, density is 5.9g/cmthree, in airChemical propertiesStable, gallium is mainly used in semiconductor industry and productionthermometerPrepare fusible metal, etc.
Indium: Indium is a silver white metal with a melting point of 156.6 ° C and a density of 7.31g/cmthree, thanleadIt is also soft, with good ductility and stable chemical properties. It is mainly used to prepare precious metal alloys,Low melting point alloy, bearing alloy, electroplating and other industries.
Selenium: Selenium is black or dark gray glassyamorphous Ingot block (red selenium and gray selenium are crystalline variants of selenium,principal componentUnchanged), which belongs to rare element, also known as semi metal.The melting point of selenium is 220 ° C, the boiling point is 685 ° C, and the density is 4.0808g/cmthree, brittle, mainly used for manufacturingrectifierSelenium light sensitive plate, copySelenium drum, alloyenamelAnd glass industry.
Tellurium: tellurium is a silver gray semi metal, a rare element, with a melting point of 450 degrees and a density of 6.24g/cmthree, brittle, with high resistance coefficientDiamagnetismMetal, so it is goodsemiconductor material 。Mainly used for makingsemiconductor device , alloy, chemical raw materials and cast ironrubber, glass and other products.
Arsenic: Arsenic is a silver gray semi metal, a rare element.The melting point of arsenic is 814 degrees, and it will sublimate at 613 degrees. Arsenic is easily oxidized in the air, and the arsenic oxide is highly toxic (commonly known asArsenic）The density of arsenic is 5.73g/cmthree, insoluble in water and insoluble inOrganic solvent, used to make alloys and semiconductor devices.
The natural reserves of platinum metals in the crust are 80000 tons, which canMining reserves71000 tons, including 50% platinum, 35% palladium, 9% ruthenium and 6% rhodium.[1]The early platinum ore came fromColumbia, mainly produced inSouth Africa, the Soviet Union, Canada, etc.
South Africa platinum mine is partly naturalPlatinum iron alloy, part of which is mixed with iron, nickel and copper in the form of sulfideSulphide oreCoexistence;ProvedRecoverable reservesAbout 18000 tons, with a total reserve of 62200 tons,Ore grade3~8g/t.The platinum group metals in Canada are mainly composed of sulfide andArsenideIt is associated with copper and nickel sulfide ores.The recoverable reserves are 280 tons, the total reserves are 497 tons, and the ore grade is 0.5~0.8 g/t.Soviet UnionPlatinum ore includes placer andparagenesisThe recoverable reserves are 6220t, the total reserves are 12440t, and the ore grade is 8-10g/t.In addition, there are paragenetic deposits in China, the United States and Australia.In all ores, platinum always coexists with other platinum group metals.In the platinum group, platinum and palladium are the largest, accounting for 90% of the total platinum group.Other rhodium, iridium, osmium and ruthenium account for only about 10% of the total platinum group.Palladium in ores of the former Soviet Union accounts for about 60% of the total platinum group, and most ores in other countries are platinum based.
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Nature and purpose
Platinum group metals are silver white except osmium, which is a blue gray metal.They are sensitive to common acids andChemical ReagentsIt has excellent corrosion resistance.
Palladium has slightly poor corrosion resistance to acid and can be quickly dissolved innitric acidMedium.Iridium, rhodium and ruthenium can resist the attack of single acid and chemical reagent, and are difficult to dissolve even in aqua regia.
Platinum and rhodium have good oxidation resistance and can maintain luster in the air for a long time.Do not wearPlatinumThe ornament is stained with oil orJavelle water, oil stain will affect the luster of jewelry;Bleach may stain jewelry.
Never putplatinum jewelry andGold jewelryAt the same time, because the gold is soft, if they rub against each other, the gold powder will be adsorbed on the platinum, making the platinum yellow, affecting the unique purity and luster of platinum.
If the platinum jewelry is inlaid with diamonds, it is recommended that the platinum jewelry should be sent to the jewelry store for inspection every year, and professional cleaning and renovation should be carried out in a timely manner to make the platinum jewelryDiamond jewelryAlways wear new.[2]
Platinum and palladium have strong adsorption capacity for gases. When the particle size is very small (such as platinum blackPalladium black）Or presentColloidal state(such as colloidal platinum), the adsorption capacity is stronger, so they have excellentCatalytic properties(SeeMetal catalyst）。Platinum group metals aretransition metal, there are multipleValenceThe most stable valence is as follows: ruthenium is+3;Rhodium is+3;Palladium is+2,+4;Osmium is+3,+4;Iridium is+3,+4;Platinum is+2,+4.They are generatedcomplex compoundThe most common is generationcoordination number4 or 6.In short, theirchemical propertyIt's complicated.
Metal production
Introduction to the Development of Platinum Group Metals Production Abroad
World Platinum Group Metalsindustrial production It started in 1778 and mainly relied onColumbiaSand ofPlatinum ore。From 1778 to 1965, Colombia produced 104 tons of PGMs, the highestAnnual output1.93 tons in 1928.1824RussiaUralAfter the mining of large placer platinum ore, it became the largest producer in the world. In 1912, the output reached 6.5 tons. By 1930, a total of 245 tons of platinum (and a small amount of iridium and osmium) were produced.In 1911, the world produced 6.189 tons of PGMs.Russia accounted for 93.1%, Colombia for 6.1%, and the United States for 0.5%,AustraliaAccounting for 0.3%.50. Howe estimated that as of January 1917, about 90% of the world's platinum group metals (249~342 tons) came from Russia.
After 1952,CanadaThe output increased significantly, exceedingSoviet UnionIt ranks first in the world.After the 1960s, the Soviet UnionSouth AfricaBecome the most important producer.The output of the Soviet Union, South Africa and Canada accounts for more than 98% of the world output.In 1980, the world had 205 tons of PGMs.Including 97.9 tons from South Africa, 96.4 tons from the Soviet Union, and 10.7 tons from other countries (mainly produced in Canada).In 1985, the world produced 230 tons of PGMs, 115 tons in the Soviet Union and 100 tons in South Africa, accounting for 93% of the world's total output.In 1986, the output was 255 tons, 124 tons in the Soviet Union and 116 tons in South Africa, accounting for 95% of the world output.Table 17-2 shows the statistics of PGM production in the world from 1921 to 1982.
South Africa is the largest platinum producing country (with annual output accounting for the worldtotal output2/3) mainly exploit BushWilderPyrogenicComplexMylensky vein in.UG-2 ore vein is exploited because of its high grade (3~8g/t, average about 5g/t), but its output changes with market supply and demand and price.Fluctuation rangeUp to one third.The largest platinum company in South Africa is Lustenburg Mining Company, accounting for 7%, and the other 3% is from Ural and the Far EastArdanregionalplacerYes.
In Canada, International Nickel Corporation accounted for 90% of the output, Yingqiao Nickel Corporation accounted for 9%, and platinum output (ton) was 40 in 1980;In 1981, 37;1982, 25;In 1983, 25.The second isimpala For the company, the corresponding annual output (ton) is 30;26；22 and 21.The third is Western Platinum, with the corresponding annual output (tons) of 2.6, 2.9, 3.1 and 2.5.In addition, Rand Mining Company (throughput3.7~5.6 tons), Atok (about 0.5 tons).South Africa supplies 1/3 of the palladium needed by the West, with an annual output of 29 tons in 1981.
Many countries are actively exploring and developing their own PGM resources, but from the perspective of their resources and production prospects, the world's PGM supply in the future will still rely mainly on South Africa and the Soviet Union, of which South Africa mainly produces platinum and the Soviet Union mainly produces palladium.
Platinum group metal production in China
Before 1965, China onlyNon ferrous metal smeltingA limited amount of platinum and palladium is recovered from by-products of.Since then, China has established and expanded the comprehensive recovery of PGMs, and its output has increased year by year.
Extraction enrichment
Placer platinum ore or containing platinum group metalsPlacer goldmineReselection methodEnrichment is availableconcentrateThe content of platinum, osmium and iridium can reach 70%~90%, which can be directly refined.
The placer platinum resources are decreasing graduallyNon ferrous metal industryDevelopment, since the 1950sPlatinum groupMetal is mainly extracted from copper nickel sulfide symbiotic ore, and a small part is extracted fromCopper smeltingExtracted from by-products.Copper nickel sulfide symbiotic orePyrometallurgyWhen,concentrateMore than 90% of the platinum group metals contained in can be enriched in copper and nickelMatte(matte).PremenstrualConverter blowingRich integrationHigh nickel matteAfter, slow cooling, grinding, floating andmagnetic separationSeparation to obtain platinum group metal containingCopper nickel alloy。Put this alloysulphidizing smelting ，Fine grindingMagnetic separation is used to separate copper and nickel to produce copper nickel alloy containing more platinum group metals.This alloy is cast into anode, and platinum group metals enter during electrolysisAnode slime。Anode slimeacid treatmentThen platinum group metal concentrate can be obtained.useCarbonyl methodWhen nickel is produced from nickel concentrate or copper nickel alloy, the platinum group is left in the carbonylation residue, which is treated with sulfuric acid orPressure leaching(See leaching) Platinum group concentrate can be obtained after other metals.ChinaJinchuan Non-ferrous Metals Company The platinum rich copper nickel alloy is obtained by remelting, fine grinding and magnetic separation of copper nickel alloy containing platinum grouphydrochloric acidLeaching and separating nickel with control potentialChlorination methodCopper is separated, and then platinum group metals are extracted.
Nickel matte with high platinum group content (such as raw materials in South Africa) is directly leached by sulfuric acid under oxygen pressure, orChlorination metallurgyPlatinum group concentrate is obtained after separating other metals.Platinum group concentrate can be directly dissolved, separated and purified, or osmium and ruthenium can be oxidized firstVolatilization separationAfter,Re separationPurification of other PGMs (see nickel smelting processValuable metalsRecycling).
In copper pyrometallurgy andElectrolytic refiningIn the process, platinum group metals and gold and silver enter the anode mud together.Use this anode mud to smelt Dol silver (containing a small amount of goldCoarse silver）Platinum group metals are enriched in Dole silver.Platinum group metals enter during pyrometallurgyCrude lead, availableSoot blowing methodIn addition to lead, Dole silver is enriched in platinum group;If crude lead is added with zinc to remove silver, platinum group metals are enriched inSilver zinc shellMedium, thenDezincificationDeDol Silver.In order to avoid palladium loss in electrolytic silver during electrolytic refining of Dole silverGold contentNormally controlled at less than 4.5%,Simultaneous controlThe gold palladium ratio is equal to or greater than 10.If some palladium and a small amount of platinum entersilver nitrateelectrolyte, availableactivated carbon adsorption , or with“xanthate”Selectively precipitate and recover.Generally, platinum group metals are enriched in silver anode slime during silver electrolysis.If the platinum group metal content is high, it can be used firstAqua regiaDissolve anode mud, and then recover it separately;If the content is low, usually use sulfuric acid to dissolve the silver, cast the residue into a coarse gold electrode, and then electrolysisWithdrawal；Platinum and palladium are enriched in electrolysismother liquorMedium, usingoxalateAfter gold precipitation, useSodium formatePrecipitated platinum and palladium for recovery;Other platinum group metals enriched in gold anode mud canRe separation。
Metal regeneration
Platinum group metals are rare and valuable, and have always attached importance to recycling.Spent catalyst, wasteElectrical componentsBroken utensils containing platinum, wasteElectroplating solutionPlatinum group metals can be recovered from the waste materials of jewelry and decoration factories.When the platinum content of these wastes is highSeparation and purification；When the content is low, it must be enriched first.Liquid waste can be replaced with cheap metal,Or plussulfideLet it sink out;Also availableElectrolytic depositionorIon exchange methodEnrichment.Solid waste can be recovered by copper or lead smelting.
Separation and purification
The extraction and refining process of PGMs varies with the composition and content of raw materials. Typical processes are shown in the figure below.Platinum group metalsconcentrateOr anode mud containing platinum group metals is dissolved with aqua regia,palladium, platinum and gold enter the solution.useHydrochloric acid treatmentTo destroy nitrosyl compounds (denitration), and then addferrous sulfateprecipitateDisbursement。plusammonium chloride, platinumAmmonium chloroplatinate【(NHfour)twoPtClsix】Precipitate out,calcinationAmmonium chloroplatinate can produceSponge platinum。The filtrate after platinum separation is added with excessAmmonium hydroxideAnd acidified with hydrochloric acid to precipitate Pd (NHthree)twoCltwo】Form of palladium, and then calcined in hydrogen to obtainSponge palladium。
Insoluble matter after the above aqua regia treatment andsodium carbonate、borax、Mitha Monk(PbO) and cokePrecious lead。Most of the lead is removed by soot blowing, and silver and residual lead are dissolved in nitric acid. Rhodium, iridium, osmium and ruthenium are enriched in the residue.Combine this residue withSodium bisulfateMelting, conversion of rhodium to solublesulfate, leaching with water, addingsodium hydroxideSink outRhodium hydroxideAnd then dissolve it with hydrochloric acid to obtain rhodochloric acid.After the solution is purified, add ammonium chloride, concentrate and crystallizeAmmonium rhodium chloride【(NHfour)threeRhClsix】。Sponge rhodium can be obtained by calcining in hydrogen.
When sodium bisulfate melts, iridium, osmium and ruthenium do not react and remain in the water leaching residue.Combine the residue withSodium peroxideandCaustic sodaMelting together and leaching with water;towardsLixiviumMiddle entrychlorineAnd distill, ruthenium and osmiumoxideForm steaming out.useethanol-Absorption of hydrochloric acid solution, reheat and distill the absorption solution, and useLyeAbsorbedOsmic acidSodium.When ammonium chloride is added to the absorption solution, osmiumammonium saltIt is precipitated in form and calcined in hydrogen to obtainosmium 。After steaming osmiumResidual fluidThe ammonium salt of ruthenium can be obtained by adding ammonium chloride, and then calcined in hydrogen to obtain ruthenium powder.
The residue after leaching ruthenium and osmium is mainlyIridium oxide（IrOtwo）, dissolved with aqua regia, precipitated with ammonium chlorideAmmonium iridium chloride【(NHfour)twoIrClsix】Iridium powder can be obtained by refining and calcining in hydrogen.
Platinum group metal powder can be made by powder metallurgy or melting in high-frequency induction furnaceMetal ingot。
To prepare high-purity platinum group metals, the metal is dissolved and repeatedly purified. The refining methods include carrier oxidation hydrolysisIon exchange, SolventextractionAnd repeated precipitation, and then precipitated out with ammonium salt. After calcination, the correspondingHigh purity metal。
Main purpose
Platinum group metals and alloys have many important industrial applications.In the past, it was mainly manufacturingDistillation kettleTo concentrateLead chamberLegal acquisitionDilute sulfuric acid, also usedPlatinum iridium alloyManufacturing standardMeter gaugeAnd weights.In the mid-19th century, Russia made platinum iridium alloy coins and circulated them in the market.In his early yearsPhotography"Platinum black printing" is adopted on the surface, and a large amount of platinum salt is used. The printed photos are beautiful and durable, and this method is generally not used.
stayPlatinum rhodium meshTo reduce the loss of platinum and rhodium, a gold palladium trap net is added.Palladium is a catalyst for hydrogenation in the chemical industry.In addition, eliminateAutomobile exhaust pollutionThe amount of catalyst used has increased rapidly.Platinum used for automobile exhaust purification in the United States was 600000 in 1978Troy ounce(1 troy ounce=31.1035 g), accounting for the totalConsumption51.3%, 660000 troy ounces in 1979, accounting for 66%.
Platinum rhodium alloy has specialCorrosion resistance, which can be used for manufacturingglass fibreOfcrucible。High quality productionoptical glassIn order to prevent molten glass from being contaminated, platinum crucibles and utensils must also be used.1968International practical temperature scaleIt is specified that the temperature measurement standard instrument within the range of 630.74 ～ 1064.43 ℃ is Pt-10Rh/PtThermocouple。The standard instrument for measuring 13.81 ～ 903.89K temperature range isPlatinum resistance thermometer, whichresistorIt must be pure platinum wire after strain free annealing at 100 ℃Resistance ratio(R100/R0) should be greater than 1.39250.
Titanium anode coated with ruthenium and platinum replacedElectrolytic cellInGraphite anode, the electrolytic efficiency is improved, and theElectrode life, YesChlor alkali industryAs an important technical improvement, it opens up a new way for ruthenium to be used in industry.OsmiumIridium alloyCan make pen tips andStylus。Palladium alloys are also used to manufacture hydrogen purification materials and high-temperature brazingsolderEtc.Platinum coated equipment is also used in the chemical industry.
Output price
Platinum group metals
Platinum Group Metals MajorCountry of productionSee Table 2 for the output of.Platinum group metalsPrice fluctuationThe overall trend is upward (Table 3).See Table 4 for consumption of platinum and palladium in various sectors, taking the United States as an example.
