INTRODUCTION

WHERE WE ARE

Zamak

The name is derived from Zinc, Aluminum, Magnesium. It consists of a group of alloys with a high Zinc content, which must be pure to 99,99%, containing in variable proportions aluminum, copper and magnesium. They are used after pressurized fusion, for plumbing fixtures, hose components and carburators.

LAP S.p.A. uses Zama of the 1° degree in their production cycle according to Law UNI 3718.

Since Zama is composed of 95 % da Zinc, we are reporting this data:
 
Chemical name Zn
French: zinc – English: zinc – German: Zink – Italian: zinco – Spanish: cinc
 

Relative atomic mass for zinc	65.39 uma	Electronic configuration of zinc	[Ar] 3d10 4s2
Value of zinc	2	Oxidation numbers of zinc	+2	Shells	2,8,18,2
Electronegativity	1.65	Aggregation state to 25 °C	Solido	Crystalline structure	Esagonale
Energy first to ionization	9.3941 eV	Energy second to ionization	17.964 eV	Energy third to ionization	39.722 eV
Atomic radius	1.53 Å	Covalent radius	1.25 Å	Ionic radius	0.74 (+2) Å
Atomic volume	9.2 cm³/mol	Specific temperature	0.39 J/gK	Vaporization temperature	115.30 kJ/mol
Fusion temperature	7.322 kJ/mol	Electrical Conductivity	0.166 · 106/cm · ohm	Thermal Conductivity	1.16 W/cmK
Fusion temperature	419.59°C	Boiling temeprature	907°C	Density to 293 K	7.14 g/cm³

Zinc

A bluish-white metal, with minimal reaction to air, it can be polished. Chemistry: Zinc is a chemical element with 30 atomic number and an atomic weight of 65,37, its symbol is Zn. It is fragile and cold, but becomes malleable and ductile between 100 °C and 150 °C. It liquifies at 419,5 °C and boiled at 906 °C; it has a density of 7,14. inalterable by the cold in dry air, in humid air it will be covered by a slight layer of hydrogencarbonate which will darken the color and protect it from deep oxidation. With high red flame it will burn with a green flame and result in ZnO. It reduces and decomposes water moisture. Common zinc is easily attacked due to the impurities that it contains, the diluted acids, generating hydrogen and zinc salts. It precipitates the more noble metals such as copper, lead, silver, etc. >From their saline solutions. It is attacked by boiling solutions of alkaline hydrates giving soluble zincate and hydrogen. Among its components we cite: oxidized ZnO obtained by combustion of zinc vapor. It is a white powder used to paint with the naim of white zinc oxide or white snow;it is not toxic and doesn’t tarnish with contact of hydrogen sulfate. The sulfide ZnS, which constitutes the natural blend, is white. The variety is crystalline and phosphorescent to light or in the presence of radioactive substances. Sulfate ZnSO4, obtained by the action of sulfuric acid on the metal, crystalizes with seven molecules of water (white glassine). It is a disinfectant. Zinc Salts are colorless or white. Their solutions with the alkali, provide a white precipitate of hydroxide, soluble in an excess of reactive. Ammonium sulfide produces a precipitate of white sulfide.

It seems that in China, zinc was already known from ancient times. In Europe, zinc alloys with copper (brass) were used before the I millennium A.C., but zinc as metallic element was prepared by Marggraf in 1746. The industrial process for the extraction of zinc from its minerals, began around the 1800’s in Slesia. To extract the metal, two groups of minerals are used: Minerals of calamine type (metasilicate hydrate of zinc) and minerals of the blend type (zinc sulfide) in which the amount of zinc is usually 40-50%. Since the zinc minerals are generally associated with the lead minerals, the preventive enrichment of the mineral is necessary and is performed by magnetic separation and flotation. To facilitate the separation of the useful parts from the sterile ones, oil or diluted sulfuric acid is added, which by superficially attacking the mineral, causes a gas to be released that encourages flotation. Depending on the countries and on the composition of the minerals, two different processes are used for extraction: 1. Thermal process. In the first phase zinc oxide is obtained, by the decomposition of the silicate (calamine) by heating at a modest temperature, or by roasting the blend to about 900 ºC. The next phase brings the metal, to the reduction of the oxide with carbon. The operation must be performed at a temperature greater than the boiling point for zinc (906 °C) in order to separate the metal from the impurities for distillation (with the exception of cadmium, more volatile). Zinc is collected in its liquid state of about 500 °C. The portion of zinc that could be lost by vapor escaping is recuperated. The metal thus obtained contains as main impurities: Cadmium, lead, copper, iron. It is then refined to a purity of 99%; for subsequent fractionalized distillation 99,99% purity can be achieved. 2. Humid process. The mineral (blend) concentrated, finely ground and roasted at a low temperature, is immersed in a solution of sulfuric acid; through the proper chemical reactions iron, cadmium and copper are eliminated. The purified solution then undergoes elctrolysis within insoluble lead anode and a cathode made of a small sheet of aluminum. The electolytic zinc is then separated from the aluminum support and fused in an oven. With this method the zinc has a purity of 99,99%.

Applications

Due to its resistance to air, zinc is utilized in slabs or sheets to cover roofs; in sheets it is also used in graphic arts and in batteries. When fused, it is used for various objects which are then covered by galvanized plastics and by a special alloy that gives them the appearance of art bronzes. Zinc has a powerful protective aspect on iron and steel when exposed to certain environments, like water, water vapor, organic substances, benzine or choride solvents. This protection is achieved through various processes.
Zinc alloys. Zinc is in the composition of numerous copper alloys: brass, special bronzes, maillechort. Zinc is the main element in Zama alloys.

Zinc: Vital Element.

Zinc as Iron and Copper is an oligoelement, indispensable for the normal functioning of the human body. It intervenes in the immune processes, regulates the fuctioning of the red blood cells, sustains growth mechanisms and is present in the reproductive organs.