Abstract: Lubricants are taught that can quickly and easily form a lubricating layer on a metal surface of a metal before plastic processing. Such lubricants preferably include a primary lubricating agent or component having a bridge complex that satisfies the following conditions: (1) the complex contains at least two central metal atoms; (2) at least one first multidentate ligand forms a bridge between two central metal atoms; and (3) at least one second multidentate ligand is bound to at least one central metal atom and has at least one coordinating atom that can coordinate with metal atoms, but which is not coordinated with any of the central metal atoms or is only partially coordinated with at least one of those central metal atoms. A third multidentate ligand is preferably also bound to one of the central metal atoms and may preferably include at least two sulfur atoms that are coordinated to the central metal atom.

Abstract: An aqueous lubricant is provided which by simple application onto metal surfaces forms lubricating films required for heavy working of metals, and which contains no oil. The aqueous lubricant is prepared by suspending or dispersing a metal chelate compound in water with a surfactant or the like. The metal chelate compound has a polydentate or multidentate chelate ligand, in which at least one of the coordinating atoms is sulfur, coordinated to the coordination site of at least one metal species selected from among zinc, manganese, iron, molybdenum, tin and antimony. When applied onto metal surfaces, the aqueous lubricant forms effective lubricating films on the metal surfaces. The lubricating films contain sulfur as coordinating atoms and therefore, extreme pressure produces sulfur radicals through decomposition by tribo-chemical reactions. The sulfur radicals are highly reactive and react rapidly with the metal surface to produce metal sulfides with a lubricating effect.

Abstract: Lubricants are taught that can quickly and easily form a lubricating layer on a metal surface of a metal before plastic processing. Such lubricants preferably include a primary lubricating agent or component having a bridge complex that satisfies the following conditions: (1) the complex contains at least two central metal atoms; (2) at least one first multidentate ligand forms a bridge between two central metal atoms; and (3) at least one second multidentate ligand is bound to at least one central metal atom and has at least one coordinating atom that can coordinate with metal atoms, but which is not coordinated with any of the central metal atoms or is only partially coordinated with at least one of those central metal atoms. A third multidentate ligand is preferably also bound to one of the central metal atoms and may preferably include at least two sulfur atoms that are coordinated to the central metal atom.

Abstract: Disclosed herein is a technique of removing metal contained in a solution through chelation, which makes it possible to preclude undesired aggregation and permit effective aggregation through an aggregating process. A surface active agent containing a hydrophobic group, a hydrophilic group and a chelating group is added to the solution to be processed, and subsequently an aggregating process is carried out. The chelating group chelates metal, the hydrophilic group prevents undesired aggregation, and the hydrophobic group is effectively aggregated in the aggregating process. Various uses are possible by selecting the charge of ligand.

Abstract: An apparatus for removing metal contained in a solution through chelation which includes a means for adding a surface active agent containing a hydrophobic group, a hydrophilic group and a chelating group to a metal containing solution held within a metal solution accommodating means. An electric field applying means is adapted to apply an electric field to the solution containing means and further means is provided for separating an aggregate from the metal contained solution.

Abstract: Disclosed herein is a technique of removing metal contained in a solution through chelation, which makes it possible to preclude undesired aggregation and permit effective aggregation through an aggregating process. A surface active agent containing a hydrophobic group, a hydrophilic group and a chelating group is added to the solution to be processed, and subsequently an aggregating process is carried out. The chelating group chelates metal, the hydrophilic group prevents undesired aggregation, and the hydrophobic group is effectively aggregated in the aggregating process. Various uses are possible by selecting the charge of ligand.

Abstract: A method of separating an aqueous colloidal solution by agglomeration into water and agglomerate of colloidal particles by applying voltage to the aqueous colloidal solution to promote the agglomeration of colloidal particles. The frequency of the voltage to be applied to the aqueous colloidal solution is increased to about 10 kHz to improve efficiency of agglomeration and suppress electrolysis of water. As the frequency is increased, hydrogen is generated earlier than the reaction of oxygen generated by the electrolysis of water with the colloidal particles, thus not oxidizing the colloidal particles. Further, as the frequency is increased, the colloidal particles tend to obtain a greater oscillation energy, thus facilitating the agglomeration thereof.