Abstract: A use of tetralin derivatives as biocidal and antifouling agents for preventing and slowing the growth of algae, molds and microorganisms. In particular, the vitamin derivatives are constituted by salts of menadione bisulfite with the heterocyclic bases triazine and piperazine.

Abstract: A vitamin K adduct, particularly suitable as vitamin supplement for feeds, constitued by menadione bisulfite bonded with an appropriate ion-exchange resin and exceptionally stabilized thereby. The adduct can be used as an antihemorrhagic additive for farm animal feeds. The high thermal stability of the vitamin adduct allows to use it in modern technologies for producing feeds in extruded form.

Abstract: C1-C12 Alkanesulfonic or Alkanedisulfonic compounds and Aminoalkanesulfonic acids or salts thereof, are used as additives in chromium plating baths to reduce anodic corrosion, improve the covering and penetrating power of the bath, reduce the surface-tension and give a bright deposit.

Abstract: A process for the production of alkaline chromates by means of oxidative disaggregation in a reactor of substances containing trivalent chromium compounds in admixture with alkali. The oxidative disaggregation is carried out in dry phase by moving the mixture within the reactor while heating the mixture by indirect heat exchange in the absence of combustion gases and under mechanical stress, and feeding to the interior of the reactor oxidizing gas. The mixture is heated to a temperature of between 500.degree. and 1500.degree. C. The oxidizing gas is fed with an oxygen concentration in a range between 8 and 100%. Gases leaving the reactor are used for the acidification of an aqueous solution of alkaline chromates which is then dried and supplied to the reactor. The reactor is a rotating tubular reactor and the mixture moves continuously through the rotating reactor.

Abstract: The chromic anhydride contained in soluble form (chromic acid) in exhausted, polluted chromium plating baths is recovered by alkalizing the exhausted chromium plating liquid to a pH comprised between 3 and 7 at a temperature of 70.degree. C. with a commercial sodium hydroxide solution, keeping the mass in reaction at this temperature for an hour and filtration separating the precipitate obtained. The filtered solution having a specific gravity of 1.25 kg/l, contains CrO.sub.3 (22% in weight) which is then reduced with sulphur dioxide to obtain a solution containing basic chromium sulphate and sodium sulphate, suitable for use as a tanning bath; in this manner pollution is avoided and the waste chromium is exploited. The solution containing CrO.sub.3 can also be introduced into a hexavalent chromium salt production cycle.

Abstract: Chromite by-products having a composition which includes FeCr.sub.2 O.sub.4 as well as iron, aluminum, magnesium, sodium, calcium and silicon oxides are directly mixed with cement mortar and with the aggregates on use, or added to the water, producing the effect of corrosion inhibition of the steel reinforcements.

Abstract: A new anhydrous sodium dichromate in flakes, Na.sub.2 Cr.sub.2 O.sub.7, m.p. 356.degree. C. (dec. 400.degree. C.) is described, characterized in that it comes in flakes with an area of approx. 1 cm.sup.2, thickness 0.5 mm and apparent specific gravity 1.10 (absolute 2.748) at 25.degree. C; it is not deliquescent, nor does it become powdery. It is prepared from dihydrate sodium dichromate or aqueous solutions thereof using a new process in two stages, namely a) evaporation-melting of the dihydrate salt or concentrated aqueous solution at a strictly controlled temperature of around 380.degree. C. and no higher, and b) flaking of the melted mass obtained thereby, as it is being rapidly cooled to 150.degree.-160.degree. C. The apparatus for carrying out the process is also disclosed; the apparatus includes a dehydrator-melter oven, a flaker rotating at 10-20 revs per minute and a heat recovery system.

Abstract: A new anhydrous sodium dichromate in flakes, Na.sub.2 Cr.sub.2 O.sub.7, m.p. 356.degree. C. (dec. 400.degree. C.) is described, characterized in that it comes in flakes with an area of approx. 1 cm.sup.2, thickness 0.5 mm and apparent specific gravity 1.10 (absolute 2.748) at 25.degree. C.; it is not deliquescent, nor does it become powdery. It is prepared from dihydrate sodium dichromate or aqueous solutions thereof using a new process in two stages, namely (a) evaporation-melting of the dihydrate salt or concentrated aqueous solution at a strictly controlled temperature of around 380.degree. C. and no higher, and (b) flaking of the melted mass obtained thereby, as it is being rapidly cooled to 150.degree.-160.degree. C. The apparatus for carrying out the process is also claimed; said apparatus consisting essentially of a dehydrator-melter oven, a flaker rotating at 10-20 revs per minute and a heat recovery system.

Abstract: Stabilized adducts of K vitaminic compounds, as menadione bisulfite or a derivative thereof and stabilizing vitamins as, particularly, nicotine amide or nicotinic acid. Feed compositions containing the same. Process for their preparation.

Abstract: An adduct of menadione and thiamine is described having the general formula C.sub.34 H.sub.36 N.sub.4 O.sub.11 S.sub.3, molecular weight 772.84 and containing the components in a molecular ratio of 2:1 respectively.This adduct is particularly intended to be added to integrator mixtures for zootechny.

Abstract: A chromium hydroxide precipitate obtained by a continuous process is described, wherein chromium containing waste waters are subjected to continuous hot treatment with acetic acid or with alkaline acetates and alkaline hydroxides at a temperature from 40.degree. C. to boiling point and at atmospheric pressure, at a pH higher than 6.5, preferably between 7 and 10, particularly about 7.5. Thus, a "sandy" type of chromium hydroxide is obtained, having a titer in Cr.sub.2 O.sub.3 of 20 to 40% by weight, which quickly filters, is easily soluble in acids, and thereby affords an easy valorization both as a tanning agent and as a raw material for preparing other chromium compound.

Abstract: A tanning material solution, containing both basic chromic sulfate and quinone groups, to which mercaptoacetic acid as a quinone hindering corrective is previously added.

Abstract: This invention relates to a two stage process for preparing 2,6-pyridinedicarboxylic acid or dipicolinic acid from 2,6-dimethyl-pyridine through oxidation of the latter in an acid environment with hexavalent chromium salts and formation of a molar addition compound between dicarboxylic acid, being formed by oxidation, and chromic anhydride in the first stage, and subsequent hot hydrolysis of the addition product so obtained, thus isolating 2,6-pyridinedicarboxylic acid therefrom in the second stage. The invention also comprises the above mentioned intermediate complex addition compound and the 2,6-pyridinedicarboxylic acid of high purity, obtained by the process according to said invention.

Abstract: A continuous process is described, wherein chromium-containing waste waters are subjected to continuous hot treatment with acetic acid or with alkaline acetates and alkaline hydroxides at a temperature from 40.degree. C. to boiling point and at atmospheric pressure, at a pH higher than 6.5, preferably between 7 and 10, particularly about 7.5. Thus, a "sandy" type of chromium hydroxide is obtained, having a titer in Cr.sub.2 O.sub.3 of 20 to 40% by weight, which quickly filters, is easily soluble in acids, and thereby affords an easy valorization both as a tanning agent and as a raw material for preparing other chromium compound.

Abstract: This invention relates to a two stage process for preparing 2,6-pyridin-dicarboxylic acid or dipicolinic acid from 2,6-dimethyl-pyridine through oxidation of the latter in an acid environment with hexavalent chromium salts and formation of a molar addition compound between dicarboxylic acid, being formed by oxidation, and chromic anhydride in the first stage, and subsequent hot hydrolysis of the addition product so obtained, thus isolating 2,6-pyridin-dicarboxylic acid therefrom in the second stage. The invention also comprises the above mentioned intermediate complex addition compound and the 2,6-pyridin-dicarboxylic acid of high purity, obtained by the process according to said invention.

Abstract: A highly selective oxidation process for preparing pyridin-carboxylic acids from pyridine compounds nucleus substituted with alkyl groups, through a carbon-carbon bond, and oxidizable to carboxyl, and from hydrosoluble hexavalent chromium compounds, in the presence of an acid.Particularly described is the oxidation of beta-picoline with sodium bichromate to obtain the sodium salt of nicotinic acid and 99.5% pure free acid, respectively.