3. Processes. .. (a) Processes of producing or separating by a chemical reaction a product a product of 1. or 2. supra, (b) chemical reaction processes not elsewhere provided for, (c) processes of separating or purifying a gaseous mixture
including a chemical reaction and (d) processes which are directed to extracting, leaching or dissolving a product or 1. or 2. supra from a mixture either, per se, or in combination with steps not otherwise provided for and for dissolving of such a product to make a water solution thereof.
AMPLIFICATION OF CLASS SUBJECT MATTER
This class provides for what is generally termed the field of inorganic chemistry. It includes inorganic compounds, nonmetallic elements and processes of producing the same involving a chemical reaction. The products are generally in a relatively pure state but may be a mixture with no other utility than as a source material for an inorganic compound or element. This includes metal compound products useful in metallurgical processes of obtaining free metals (see Subclass References to the Current Class, below).
A mixture of an inorganic compound or nonmetallic element with a preserving agent whose sole function is to prevent physical or chemical change of such compound or element is provided for in this class, unless the mixture is disclosed or claimed as having a function or utility provided for in the composition classification (see Subclass References to the Current Class, below). Also, processes of merely incorporating a preservative are included in this class.
The rules for determining class placement of the original reference (OR) for claimed chemical compositions are set forth in the class definition for compositions. See the (17) Note under LINES WITH OTHER CLASSES AND WITHIN THIS CLASS for additional information. This class also provides for processes of separating or purifying a normally gaseous mixture by a chemical reaction, unless the resulting mixture has a disclosed utility provided for in the composition classification.
This class is also the residual class for all chemical reactions not provided for elsewhere, e.g., a reactive process where no specific product compound is disclosed.
For this class, the nonmetallic elements are: the halogens including astatine, the inert gases, hydrogen, boron, carbon, silicon, nitrogen, phosphorus, oxygen, sulfur, selenium and tellurium.
This class is also the class for extracting, leaching or dissolving processes not provided for elsewhere (see Subclass References to the Current Class, below).
LINES WITH OTHER CLASSES
(1) Note. An inorganic compound for this class must contain a nonmetallic element; intermetallic compounds, or union of metallic elements only are excluded and will be found in
Class 420.
(2) Note. Subclasses which recite nitrogen or hydrogen in their titles do not include the ammonium radical (NH4[supscrpt]+[end supscrpt]) within their definitions; the NH4[supscrpt]+ [end supscrpt]radical is considered to be, and is treated as, an entity or element, equivalent to Na, Ca, N, etc.
(3) Note. When a radical is indicated in a subclass title, (e.g., sulfide, carbonate, phosphate, etc.), all forms thereof (i.e., the acid forms, such as HSO3[supscrpt]- [end supscrpt], HCO3[supscrpt]-[end supscrpt], HPO4[supscrpt]2-[end supscrpt], H2PO4[supscrpt]-[end supscrpt]) are also included within the definition, unless specifically stated otherwise. Generally, however, in the metal recovery area, subclasses 1+, only the radicals listed in the titles are involved and no other. For example, in subclass 36, "sulfating" means that only the sulfate (SO4[supscrpt]2-[end supscrpt]) radical is intended. In the remaining areas of the schedule all forms of the radical are generally intended.
(4) Note. Use of a chemically reactive material, e.g., acid or base is considered to involve a chemical treatment for this class, unless there is evidence to the contrary or where otherwise stated, (see subclass 210, reference to Class 95, for example).
(6) Note. Processes of purification which involve oxidation or chemical conversions of impurities, as well as those processes wherein the compound sought to be purified is first converted into some other form or derivative from which it is reverted to the original compound are also considered to be chemical treatment.
(7) Note. Processes of preparation of an inorganic compound or a nonmetallic element which include chemical treatment or preparation are classified in the appropriate compound or element subclass, unless a process subclass is specifically provided therefor under the compound or element subclass, even though combined with a purely physical operation precedent, subsequent, or both. However, a patent containing a claim to the product and a claim to the process of manufacture thereof, which process is indented under the product subclass, should be placed in the outdent (product subclass) and cross-referenced to the other. A claim to the product of making it is considered to be a product claim and should be classified in the appropriate product subclass and cross referenced to the process, if any. (8) Note. Processes of preparation or treatment of inorganic compounds and nonmetallic elements which involve only physical treatment except for extracting, leaching or dissolving, per se, are classified in 23, Chemistry:
Physical Processes, subclasses 293+ unless specifically provided for in some other main class. When extracting, leaching or dissolving processes are combined with significant crystallization steps, see Class 23, Chemistry: Physical Processes, subclasses 295+. Also see Class 23, Chemistry: Physical Processes, subclasses 293, 294 and 306 thru 308 for extracting, leaching or dissolving which may be combined with physical steps therein provided for. When patents include claims to a physical process and also claims to the compound or element treated, the original patent is classified in Class 423 in the appropriate subclass providing for the compound or element and cross-referenced to the appropriate process subclass in Class 23.
(9) Note. Varying the amount of water of crystallization or hydration is considered to involve a chemical reaction; merely changing from one crystalline form to another or from or to a non crystalline form is not considered to be a chemical reaction.
(10) Note. The combination of a nominal molding step and a chemical reaction is properly classified in Class 423. See definition of Class 264 for examples of "nominal" molding steps.
(11) Note. The combinations of a chemical reaction and magnetic separation is in Class 423.
(12) Note. A compound having water of hydration or crystallization attached thereto is classified with the basic compound unless there is a specific subclass provided for the hydrated compound. In this respect, the water (H2O) is treated as a unit and the hydrogen and oxygen therein of themselves do not cause classification in the oxygen area (579+) or the hydrogen area (644+).
(13) Note. A material or substance containing a metal or other element in a range of absolute values or mole ratios compared to another metal or other element, (e.g., 1.7-3.5 parts, mole ratio of M to X in the range of 1.1-3.7, etc.), will be considered proper for a composition class; if the metal or other element is present in specifically defined whole integer values, (e.g., 1, 2 or 3 parts, etc.), it will be considered a compound properly classified in Class 423. Similarly if atoms or molecules in a chemical formula are not present as whole small integer values or cannot be multiplied by a factor to yield integer values, then the substance represented by the formula will be considered to be a mixture or composition classifiable in a locus other than Class 423. However, see (1) Note in subclass 328 for exception to general rule stated above.
(14) Note. A water solution (whether preserved or not) of a Class 423 compound or element is classified in Class 423 unless its use is claimed or a single use is disclosed, in which case classification in the use class is indicated.
(15) Note. When a patent includes (1) a single claim directed to the formation of 2 or more desired products, or (2) plural, equally comprehensive claims defining processes or products wherein the individual claims would be classified in separate classes, the following rules apply: (1) As between Class 423 and other classes providing for compounds the patent is placed in Class 423. (2) As between Class 423 and Class 75 the patent is placed in Class 75. (3) As between Class 423 and classes providing for compositions, the patent is placed in the composition class.
(16) Note. Where a process includes a step of recovery of the energy in a fluid (e.g., expansion in a motor to produce mechanical or electrical power, use in a heat exchanger for utilization outside of the process, etc.) the intent of the patentee must be considered for proper classification. If the intent is to conduct the chemical reaction, make the product or purify a gas or separate a mixture as provided for in Class 423 and recovery of the energy in the fluid is simply for economic reasons the classification is proper for Class 423. If the intent of the chemical reaction, is to increase the energy level in the fluid for the purpose of producing the mechanical or electrical power, then classification in another main class is indicated. If the power produced is used in the process, e.g., pumping, refrigeration, heat exchange, etc. classification in Class 423 in proper.
(17) Note. The rules for determining Class placement of the Original Reference (OR) for claimed chemical compositions are set forth in the Class Definition of Class 252 in the section LINES WITH OTHER CLASSES AND WITHIN THIS CLASS, subsection COMPOSITION CLASS SUPERIORITY, which includes a hierarchical ORDER OF SUPERIORITY FOR COMPOSITION CLASSES.SEE OR SEARCH THIS CLASS, SUBCLASS:
1+, for treating mixture to obtain metal containing compound (see the Class Definition, above).
265+, .for products or processes comprising a compound or a nonmetallic element physically interrelated with another substance which serves to improve, protect or modify the product, which substance does not take part in the reaction, which makes the product, but is added to the reaction or to the product or is made by a separate and distinct reaction.
658.5, for extracting, leaching or dissolving processes.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
23, Chemistry: Physical Processes, for processes of preparing or treating inorganic compounds or nonmetallic elements which involve only physical treatments except for extracting, leaching, or dissolving, per se, and not
specifically provided for in some other class; for processes for analysis which involve a chemical reaction.
48, Gas: Heating and Illuminating, for processes for making heating and illuminating gas in general and processes and apparatus for purifying a heating and illuminating gas; processes involving a chemical reaction for making or purifying heating or illuminating gas consisting of a single element or organic compound, per se, are classified in Class 423.
53, Package Making, appropriate subclasses especially
428+, for methods of manufacturing chemical compounds followed by a subsequent packaging step.
65, Glass Manufacturing, for a process or apparatus for chemically manufacturing silicon or silicon dioxide (arbitrarily considered to be glass for Class 65) combined with significant shaping or heat treating. 71, Chemistry: Fertilizers, appropriate subclasses for compositions, and processes of making such compositions, having a nutrient action on plant growth. See (1) Note in the definition of Class 71 and (13) Note and (15) Note in the definition of Class 423 for lines between these two classes.
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, the line with the Class 75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, is generally as follows: Class 75 provides for metals and processes for their manufacture. Class 423 provides for chemically modifying metal bearing compositions to form intermederiary products which comprise inorganic compounds even if intended for subsequent reduction to free metals. When it is not clear from the claimed disclosure whether the product produced is an intermediary of a free metal, it is assumed to be intermediary. A smelting process is assumed to produce a free metal unless otherwise stated. Class 75 provides for ore beneficiating processes which claim a sintering or agglomerating step, even though the production of a free metal is not claimed, and compounding of ingredient to make a composition which is in better form for pyrometallurgy, even though some chemical reaction is involved. Patents including claims classifiable in Class 423 and equally comprehensive claims classifiable in Class 75 are classified in Class 75 and cross-referenced to Class 423. Processes resulting in the production or separation of undesired metallic material, e.g, impurities, during the manufacture of Class 423 compounds are classified in Class 423. If the metal is a desired material, however, the patent is classified in Class 75. See also the note to Class 420, Alloy or Metallic Composition below. As between Class 75 and Class 423, intermetallic compounds are in Class 75. Processes resulting in the production or separation of
undesired metallic material, e.g., impurities, during the manufacture of Class 423 compounds are classified in Class 423. If the metal is a desired material, however, the patent is classified in Class 75.
95, Gas Separation: Processes, for processes of a purely physical nature involving steps resulting in separation of a gas from a fluid mixture comprising (a) a gas and solid or liquid particles entrained therein, (b) a liquid and gas entrained therein, or (c) a plurality of gases. For patents to be placed in Class 423, a particular chemical must be claimed and the chemical reaction must be inherent or disclosed. Broadly reciting the separating material as a "chemical" or as "gas purifying material" does not exclude the patent from Class 95. Absorption and adsorption are not considered chemical reactions in this respect. Processes for separating a gaseous fluid mixture having therein ammonia (NH3) or acid anhydrides (e.g., CO2, SO2, etc.) by contacting the gaseous fluid mixture with water and thus dissolving these gases out of the gaseous fluid mixture are in Class 95, notwithstanding the fact that a chemical reaction occurs in the solution and that ammonium hydroxide or the acids are formed. See also, search class note to Class 95 in Class 423,
210,.
106, Compositions: Coating or Plastic, appropriate subclasses for coating or plastic compositions not otherwise provided for. For the line between Classes 106 and 423. In regard to materials and ingredients, e.g., pigments, see the note to the definition of Class 106 under the heading "Materials or Ingredients". See also (13) Note and (15) Note in the definition of Class 423 and (4) Note in
265, of that class.
117, Single-Crystal, Oriented-Crystal, and Epitaxy Growth Processes; Non-Coating Apparatus Therefor, for processes and non-coating apparatus for growing therein-defined single-crystal of all types of materials, including inorganic or organic.
134, Cleaning and Liquid Contact With Solids, appropriate subclasses, especially
2+, for the process of treating a mixture to remove foreign matter from the surface. The line between this Class 134 and Class 423 is as follows: in Class 423 the intent is to recover a metal compound from a mixture thereof, while in Class 134, the intent is merely to clean the mixture, whether or not the removed foreign matter is later treated to recover valuable by-products.
148, Metal Treatment, for processes for making case hardened metals and the corresponding products (e.g., carbided or
nitrided metals) in which a metal is treated so as to form the nitride or carbide of the metal in more or less as a layer thereon, but which layer varies in composition towards the inside, the intention being to form case hardened metal, not to form a definite compound for recovery thereof. 162, Paper Making and Fiber Liberation, appropriate subclasses for process of chemically preparing or recovering inorganic compound with a fiber liberation step, and especially
29+, for processes of regenerating, for purposes of reusing, a fiber treating liquor, even though a compound or nonmetallic element for Class 423 is recovered. For the line between this Class 162 and Class 423 in regard to regeneration, the intent of the disclosure must be considered. If there is an intent to regenerate, reconstitute, reclaim or recycle the waste or used liquor being treated, whether or not a Class 423 product is recovered, classification is in Class 162.
201, Distillation: Processes, Thermolytic, appropriate subclasses for a process of carbonizing solid carbonaceous material, or for calcining coke to produce a coke or other impure carbon containing material, not otherwise provided for. A document having claims to both the process of coking and the additional steps of producing carbon black will be classified in Class 423 and cross referenced to Class 201.
203, Distillation: Processes, Separatory, for a process of separating a liquid mixture by vaporizing and condensing a portion thereof to isolate in the distillate or in the residue a relatively pure compound which was present as such in the original mixture, and for a process including a chemical reaction and a separatory distillation operation when the chemical reaction merely facilitates the isolation by the distillation process of a pre-existing substance in the original mixture. Class 423, Inorganic Chemistry, takes a process of preparing a compound and isolating it by a separatory distillation process or vaporizing a mixture and contacting the vaporous mixture with a substance which purified the mixture and prepares a compound for that class.
204, Chemistry: Electrical and Wave Energy, for processes of producing an inorganic compound or nonmetallic element by directly employing electrical or wave energy. The general line between this Class 423, and Class 204 is as follows: Class 423 provides for (1) process steps falling within the definition of Class 204 wherein a simultaneous or subsequent chemical reaction takes place which modified the product of the Class 204 to produce a different compound or element, and (2) branching processes wherein one of the branches comprises a process falling within the definition of Class 204 and at least one branch falls within the definition of Class 423. Class 204 takes processes wherein an initial or preparatory reaction of the type provided for in Class 423 is followed by process step of the type provided for in Class 204 which
modifies the product of the initial reaction. In processes where a useful by-product is formed, the patent is classified accordingly.
(1) Note. If electrolysis takes place in a reagent which immediately reacts with a product of the electrolysis to yield a Class 423 product, classification is proper for Class 423.
209, Classifying, Separating, and Assorting Solids, appropriate subclasses, for processes of separating a mixture of compounds by magnetic action. However, processes which include both a chemical reaction and a magnetic separation are classified in the appropriate chemical class, e.g., Class 423, etc.
210, Liquid Purification or Separation, for chemical processes where the main intent is to purify a liquid, not to purify or recover a compound or nonmetallic element for Class 423, in regard to treatment of an effluent or waste liquor, the intent of the disclosure must be considered. If it be the main intent to purify the effluent liquor for disposal, classification is in Class 210 even though a product for Class 423 is recovered as an incident to the purification. If the main intent is to treat the effluent to recover a Class 423 product then classification in Class 423 is indicated. If the disclosure contains both intentions and it cannot be determined which is the primary intention, then classification is in Class 423 with cross reference to Class 210 where necessary.
252, Compositions, appropriate subclasses, for compositions of matter not otherwise provided for. See the definitions of Class 252 for its scope and the notes thereto for classification of other compositions. See also (13) Note and (15) Note in the definition of Class 423.
260, Chemistry of Carbon Compounds, appropriate subclasses, for claimed chemical processes in which an organic compound is the end result, even though the intent is to make an inorganic compound from this organic intermediate. However, a process which results in several different chemical compounds, one of which is classifiable in Class 423 and another is classifiable in Class 260, is classified in Class 423 and cross referenced into Class 260, except where the compound classifiable in Class 423 is only incidentally produced by the reaction, such as, for example, HC1 and is not an objective of the process.
376, Induced Nuclear Reactions: Processes, Systems, and Elements for appropriate subclasses for changes in the chemical nature of materials brought about by nuclear reactions; and 156+, and 323+ for production of materials, other than or in addition to the conversion of nuclear fuel, by means of nuclear reactions.
420, Alloys or Metallic Compositions, appropriate subclasses for alloys, intermetallic compounds or compounds or composition containing a continuous phase of metal and methods of making them. See the class definition of Class 420 for the line between Class 420 and Class 75 for processes fo making alloys.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing,
1, 44 for processes for disinfecting, deodorizing, preserving, or sterilizing. Inorganic compounds or nonmetallic elements claimed with an additive which only serves to preserve the product are in Class 423. See also the notes in Class 423, subclasses 265+ and subclasses 45+ for chemical reactors and apparatus for carrying out chemical physical processes.
424, Drug, Bio-Affecting and Body Treating Compositions, appropriate subclasses for a Class 423 product combined with an additive which is claimed or solely disclosed as having a Class 424 utility. A Class 423 product having combined therewith an additive which protects the product, itself against biological attack is proper for Class 423, see
265+,.
426, Food or Edible Material: Processes, Compositions, and Products,
160+, for baking powder compositions, which in some cases are made to deliberately contain impurities to stabilize the same and to cause proper reaction rates. In many instances, the compound is calcium acid pyrophoshate and the impurity is a calcium or aluminum compound.
428, Stock Material or Miscellaneous Articles, appropriate subclasses, for metallic compounds having specific outer structure, especially
379+, for a structurally defined or coated rod, strand, fiber or particle which may include a metal compound; subclasses 432 and 469+ for a non structural composite web or sheet including a layer of a metal compound.
429, Chemistry: Electrical Current Producing Apparatus, Product, and Process, 188+, for electrolyte compositions; subclass 247 for materials used to make a battery separator; and other appropriate subclasses having compositions combined with structure.
432, Heating,
1+, for a residual process of heating. The line between
Classes 423 and 432 is generally as follows: Class 423 takes heating processes which involve a chemical reaction to produce an inorganic compound or nonmetallic element. Materials identified by, terms such as "lime", "limestone" and "gypsum", are considered to be compounds for Class 423, but terms such as "cement" and "clay" are not. Residual processes which do not include a chemical reaction or do not result in a compound are in Class 432. The terms "calcining", "burning", "removing water of hydration", etc. are considered to involve a chemical reaction.
435, Chemistry: Molecular Biology and Microbiology, for processes of making separating or purifying compounds or elements by operations that include fermentation, and compositions and apparatus that are specialized for use therein and processes of making such compositions for such use.
504, Plant Protecting and Regulating Compositions, appropriate subclasses for compositions, and processes of making such compositions, having a stimulating or regulating action on plant growth. See (13) Note and (15) Note in the definition of Class 423 for lines between these two classes.
100+, for high temperature (Tc 30 K) superconducting materials, per se, or subclasses 300+ for processes of producing same.
585, Chemistry of Hydrocarbon Compounds, appropriate subclasses for a claimed chemical process to synthesize a hydrocarbon. When a process produces an inorganic compound for Class 423 and a hydrocarbon compound for Class 585, both of which are intended to be recovered, the patent is classified as an original in Class 423 and cross-referenced to Class 585.
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the process of destruction of hazardous or toxic waste by way of incineration heating or other chemical reactions when the destruction of the waste is the intended purpose, Class 423 takes all intended production or recovery of marketable products in the form of inorganic compounds or elements.
GLOSSARY:
Terms used throughout the schedule and definitions are to have the meanings ascribed below. In some instances all the limitations found below may not have been included in the subclass definitions; all discrepancies should be resolved in favor of the following definitions. ABSORPTION
The ability of a substance to retain or concentrate gases, liquids or dissolved substance (absorbate) within its bodies.
ADSORPTION
The ability of a substance (usually a solid) to retain or concentrate gases, liquids or dissolved substances (adsorbate) upon its surface.
ALKALI METALS
The metal elements of the first group of the periodic system, consisting of Li, Na, K, Rb, Cs.
ALKALINE EARTH METALS
The metal elements in Group II A of the periodic system, consisting of Mg, Ca, Sr, Ba.
BINARY COMPOUND
A chemical compound consisting of 2 elements only with 2 or more atoms; e.g., NaC1, FeC13, Fe304, etc.
CHALCOGEN Also known as chalcogenide(s), the elements oxygen, sulfur, selenium, tellurium and polonium.
CATALYST
A substance which either increases or decreases the speed of a chemical reaction without itself undergoing a permanent change.
COMPLEX COMPOUND
A chemical combination of two or more compounds or ions; e.g., 4 KCN and Fe (Cn)2 give the complex compound K4Fe (Cn)6; 2 HF and Si F4give the complex acid H2 Si F6. An electrically charged radical or group of atoms, e.g., Cu (NH3) 2[supscrpt]+[end supscrpt], is a complex ion.
COMPOUND
The elements or compounds comprising a material or produced from it by analysis.
COMPOUND
A substance whose molecules consist of unlike atoms, whose
constituents cannot be separated by physical means, whose properties are entirely different from those of its constituent elements and which contains definite proportions of its constituent elements, depending on their atomic weights.
FLOTATION
A process for the concentration of selective separation of components of ores by grinding the ores with a frothing agent, floating them on water and agitating the mixture with compressed air, causing the wet gangue (earthy portion of the ore) to settle and permitting the concentrated ore to be skimmed off. FLUIDIZED BED
A mass of solid particles maintained in a state of constant turbulent motion in a gas stream, resulting in a suspension of finely divided particles in a stream of gas thus increasing the surface area and therefor surface activity of the particles.
HALOGENS
Also known as halogenides, the nonmetallic elements of the seventh group of the periodic system and consisting of F, C1, Br, I, At.
INERT GASES
The noble gases of the zero group of the periodic system, consisting of He, Ne, Ar, Kr, Xe, Rn, which have no valency and combine only with great difficulty, if at all, with other elements.
ION EXCHANGE
A process in which ions are chemically transferred from a material to a liquid or solid separatory substance or exchanger which, because of its chemical structure of loosely bound ions, has an affinity for certain ions and gives up some of its own ions to the material. The exchange occurs between ions of like charge; the exchanger substance can usually be regenerated by passing another material through it to elute the previously sorbed ions and replace them with the original kind of loosely bound ions. These ion exchange substances are usually resins or zeolites or chelates.
IRON GROUP METALS
Those metals in the central part of the third period of the periodic system consisting of Fe, Co and Ni, all of which form colored salts and 2 or more series of compounds.
LEACHING The process of extracting or dissolving a soluble component from a mixture by contacting the mixture with a solvent, resulting in dissolution or solution of the solubles and leaving an insoluble material.
(Note. Solution of a substance in a normally solid, molten material is not considered to be "leaching" as defined above.)
LIQUID-LIQUID EXTRACTION
The process of transferring a substance (fluid or solid) from one liquid phase in which it is dispersed or dissolved to a second liquid phase which is immiscible with the first liquid.
NONMETALLIC ELEMENTS
The electronegative elements on the right of the periodic system, which generally exist in several stages of oxidation and whose oxides form acids. See main class definition for list of nonmetals for this class.
ORGANIC COMPOUND
A compound as defined in the definition of Class 260, Chemistry of Carbon Compounds as qualified by (34) Note.
PLATINUM METALS
A group of noble metals that occur together in nature and form 2 groups in the periodic system, i.e., Ru, Rh, Pd, Os, Ir and Pt.
PROMOTER
A substance which stimulates or aids the effect of a catalyst. RADIOACTIVE
Able to give off rays by spontaneous disintegration. The radioactive elements are usually those having an atomic number of 84 or greater and the phenomenon of radioactivity is not affected by chemical or physical influences.
RARE EARTHS
The oxides of the rare earth metals consisting of the elements having atomic numbers 21, 39, 57-71, inclusive.
RECOVERY
The extraction or removal of a valuable constituent from a raw material, by-product or waste product.
REFRACTORY METALS
Those metals in Group IV B, V B and VIB of the periodic system, consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, some of which are used in making bricks or cement which resist heat and are slow to soften.
TERNARY COMPOUND
A chemical compound consisting of 3 elements only, such as NaOH, H2SO4, KCN, etc.
VOLATIZING Converting a normally solid or liquid material into a gas or vapor state; mere volatization of water or a solvent is excluded under this definition.