Lithium ( /ˈlɪθiəm/ LITH-ee-əm) is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and inflammable. For this reason, it is typically stored in mineral oil. When cut open, lithium exhibits a metallic luster, but contact with moist air corrodes the surface quickly to a dull silvery gray, then black, tarnish. Because of its high reactivity, lithium never occurs free in nature, and instead, only appears in compounds, which are usually ionic. Lithium occurs in a number of pegmatitic minerals, but due to its solubility as an ion is present in ocean water and is commonly obtained from brines and clays. On a commercial scale, lithium is isolated electrolytically from a mixture of lithium chloride and potassium chloride.
The nuclei of lithium verge on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides. Because of its relative nuclear instability, lithium is less common in the solar system than 25 of the first 32 chemical elements even though the nuclei are very light in atomic weight. For related reasons, lithium has important links to nuclear physics. The transmutation of lithium atoms to helium in 1932 was the first fully man-made nuclear reaction, and lithium deuteride serves as a fusion fuel in staged thermonuclear weapons.
Lithium and its compounds have several industrial applications, including heat-resistant glass and ceramics, high strength-to-weight alloys used in aircraft, lithium batteries and lithium-ion batteries. These uses consume more than half of lithium production.
Trace amounts of lithium are present all organisms. The element serves no apparent vital biological function, since animal and plants survive in good health without it. Nonvital functions have not been ruled out. The lithium ion Li+ administered as any of several lithium salts has proved to be useful as a mood-stabilizing drug due to neurological effects of the ion in the human body.
What are Borates?
Borates are naturally-occurring minerals containing boron, the fifth element on the Periodic Table. Trace amounts exist in rock, soil and water. Plants need them to grow. People need borates, too, as an important part of a healthy diet and an essential ingredient in many products necessary for an acceptable standard of living.
The element boron does not exist by itself in nature. Rather, boron combines with oxygen and other elements to form boric acid, or inorganic salts called borates. Despite the millions of tons of industrial borates mined, processed and distributed around the world every year, far larger quantities of boron are transferred around the planet by way of natural forces. Rain, volcanic activity, condensation and other atmospheric activities redistribute at least twice as much boron as all commercial practices combined.
Metabolizing Effects - In certain organisms, borates can inhibit metabolic processes. This makes them useful in controlling insects, bacteria and fungi in everything from construction timbers to cosmetics.
Bleaching Effects - Another key chemical effect comes into play in laundry detergents and other cleaning products, where borates are important components in bleaching and stain removal.
Buffering Effects - The chemical properties of borates serve to balance acidity and alkalinity in many applications. Detergents, fireworks and film processing solutions all rely on borates for a stable pH.
Dispersing Effects - Borates are able to bond with other particles to keep different ingredients dispersed evenly and are used to control viscosity in paints, adhesives and cosmetics.
Vitrifying Effects - Borates modify the structure of glass to make it resistant to heat or chemical attack. Similarly, they facilitate the production of ultra-thin LCD screens, functional fiberglass and beautiful ceramic tiles and glazes.
Inhibiting Effects - Borates interact with surfaces containing iron to form a coating that protects the metal from corrosion. They are important additives in products as diverse as antifreeze and aerosol cans.
Flame-Proofing Effects - Combined with zinc, borates are used to retard flames and suppress smoke in polymers. Borates also act as a flame retardant in cellulose insulation.
Neutron-Absorbing Effects - Borates absorb neutrons in applications ranging from nuclear containment shields to treatments for cancer. While borate applications number in the thousands, chief among them are:
Agriculture: Boron is an essential micronutrient for plants, vital to their growth and development. Without sufficient boron, plant fertilization, seeding and fruiting are not possible. On every continent of the world, crop yields and food quality are diminished due to insufficient boron concentrations in the soil. These deficiencies can be corrected with borate fertilizers. In areas of acute deficiency, borates can increase crop yields by 30 to 40 percent.
Ceramics: Borates have been an essential ingredient in ceramic and enamel glazes for centuries, integral to affixing glazes or enamels, and enhancing their durability and luster. Borates now are gaining acceptance as an essential ingredient in ceramic tile bodies, allowing manufacturers to use a wider range of clays, heightening productivity and decreasing energy usage.
Detergents and Personal Care Products: Borates enhance stain removal and bleaching, stabilize enzymes, provide alkaline buffering, soften water and boost surfactant performance in detergents and cleaners. Their biostatic properties control bacteria and fungi in personal care products. New trials demonstrate that adding borates to laundry soap bars significantly improves their cleaning action and reduce levels of dirt redeposition.
Diet: Not surprisingly, people get the boron they need by eating plant-derived food. Studies indicate that people in a wide variety of cultures consume one to three milligrams of boron per day through a combination of foods and drinking water in their local diets. Although it has not been proved yet that humans need boron to live, there is almost universal agreement in the scientific community that boron is nutritionally important to maintain optimal health.
Fiberglass: Borates are an important ingredient in both insulation fiberglass - which represents the largest single use of borates worldwide - and textile fiberglass, used in everything from circuit boards to surfboards. In both products, borates act as a powerful flux and lower glass batch melting temperatures. They also control the relationship between temperature, viscosity and surface tension to create optimal glass fiberization.
Glass: Borosilicate glass is the foundation for all heat-resistant glass applications and the myriad products they make possible - from cathode ray tubes to Pyrex® cookware. Borates increase the mechanical strength of glass, as well as their resistance to thermal shock, chemicals and water.
Polymer Additives: Zinc borates are used primarily as a fire retardant synergist in plastics and rubber applications. They also can function as smoke and afterglow suppressants, anti-tracking agents, and can be used in polymers requiring high processing temperatures. Zinc borates can be found in polymers ranging from electrical parts and automobile interiors to wall coverings and carpeting.
Wood Treatments: Borate-treated wood is on the rise as a safe and long-lasting method to protect homes and other structures from wood-destroying organisms. Borate-based preservatives can be used to treat solid wood, engineered wood composites and other building materials like studs, plywood, joists and rafters. Borates prevent fungal decay and are deadly to termites, carpenter ants and roaches - but are safe for people, pets and the environment.