Lime-sulfur

Sprayometer (Parrot and Stewart). This hydrometer which is used in determining the density of lime sulfur solutions has two scales one scale is graduated from 0° to 38° Baume and the other scale is from 1.000 to 1.350 specific gravity. 

Miscellaneous. Both whiting and hydrated lime are used as diluents and carriers of pesticides, such as lime—sulfur sprays, Bordeaux, calcium arsenate, etc. The most widely used bleach and sterilizer, high test calcium hypochlorite, is made by interacting lime and chlorine (see Bleaching AGENTS). Calcium and magnesium salts, such as dicalcium phosphate, magnesium chloride, lithium salts, etc, are made directly from calcific and dolomitic lime and limestone. 

Lime-Sulfuric. Recovery of citric acid by calcium salt precipitation is shown in Figure 3. Although the chemistry is straightforward, the engineering principles, separation techniques, and unit operations employed result in a complex commercial process. The fermentation broth, which has been separated from the insoluble biomass, is treated with a calcium hydroxide (lime) slurry to precipitate calcium citrate. After sufficient reaction time, the calcium citrate slurry is filtered and the filter cake washed free of soluble impurities. The clean calcium citrate cake is reslurried and acidified with sulfuric acid, converting the calcium citrate to soluble citric acid and insoluble calcium sulfate. Both the calcium citrate and calcium sulfate reactions are generally performed in agitated reaction vessels made of 316 stainless steel and filtered on commercially available filtration equipment. 

Fig. 3. Lime-sulfuric recovery process for citric acid.

By-Products. The biomass from the fungal fermentation process is called mycellium and can be used as a supplement for animal feed since it contains digestable nutrients (25,26). The lime-sulfuric purification and recovery process results in large quantities of calcium sulfate cake, which is usually disposed of into a landfill but can find limited use in making plaster, cement, waUboard, or as an agricultural soil conditioner. The Hquid extraction purification and recovery process has the advantage of Htde soHd by-products. 

Sulfur has long been known for its properties as a pesticide and a curative agent. Homer spoke of the pest-averting sulfur as far back as 800—1000 BC, Hippocrates (400 Bc) considered sulfur sa an antidote against plague, and Dioscorides (100 ad) used sulfur ointment in dermatology (244). In 1803, the use of a lime—sulfur protective treatment for fmit trees was reported, and in 1850 sulfur dust was used to protect foHage (245). In 1891 sulfur dust was used on soil to control onion smut (246). 

Schwefel-indium, n. indium sulfide. -jodUr, n. sulfur monoiodide, -kadmium, n. cadmium sulfide. -kalium,n. potassium sulfide, -kalk, m. lime-sulfur, -kalkbrtihe, /. lime-sulfur mixture (for spraying), -kalzium, n. calcium sulfide, -kammer, /. sulfur chamber, sulfuring room, sulfur stove, -karbolsaure, /. sulfo carbolic acid, -kastenbleiche, /. (Dyeing) stoving. 

In addition to their concern regarding spray residues of the lead arsenate and organic types, canners whose fruits are sprayed with lime sulfur have reason for concern over the presence of sulfur in their canned products. The presence of elemental sulfur or simple compounds of reduced sulfur in canned foods, especially in those products having an acid character, is objectionable, not only because it may be the source of sulfide flavor and staining, but also because it may actively accelerate the formation of hydrogen by the corrosive action of the product on the container. 

The development of resistant strains of an insect to a given insecticide is not new. Melander (7) in 1914 pointed out that the San Jose scale in Washington had developed a resistance to lime-sulfur sprays. Recently Babers (1) of the Bureau of Entomology and Plant Quarantine brought together an excellent evaluation and summary of the literature dealing with the development of insect resistance to insecticides he lists 111 references to work on this phenomenon. 

In 1875 Pollacci (7) reported grape leaves treated with sulfur produced hydrogen sulfide gas. Recently it has been reported that hydrogen sulfide gas is produced by sulfur-dusted lemons and oranges (22). This gas which emanates from sulfured plants is also produced by the reactions of ingredients in the widely used lime-sulfur sprays. St. John and Groves (9) have excellently reviewed the chemistry of these mixtures. 

Black knot is a common disease of plum trees. This fungal infection produces swollen, knobby black galls on branches. Prune out affected branches during the winter, then spray lime-sulfur as buds swell in spring and again... 

Bacterial leaf spot causes small, angular black spots on leaves. Leaves may turn yellow and drop early. Spray lime-sulfur every 10-21 days until leaf drop if weather is wet or humid, or if the spots are spreading. 

What to do Look for resistant cultivars. In fall or late winter, prune off infected limbs, 6-12 in. (15-30 cm) below the knots disinfect pruners in between cuts with a 10% bleach solution (1 part bleach to 9 parts water). Destroy the prunings. Remove any wild plum or cherry trees nearby. For persistent infections, apply 2 sprays of lime-sulfur, 7 days apart, before the buds begin to grow in spring. 

A large amount of potash is imported, in contrast to other mineral production in the United States. In 1999 2.8 billion lb of potash were processed in the U.S., but 10.2 billion lb were imported. This is a good time to compare some important minerals that we use to make various key inorganic chemicals, shown in Fig. 6.6. Phosphate rock leads in production. Salt is near it in production (not shown), followed by lime, sulfur, soda ash, and potash. 

Uses of sulfur. In the elemental form, sulfur is used (1) in the vulcanization of rubber (2) in the manufacture of black powder (3) as a fungicide (in powder form), particularly in growing grapes and (4) as lime-sulfur spray for fruit trees. Although the preceding uses require considerable amounts of this element, the great bulk of the world s production of sulfur goes into the manufacture of sulfur dioxide, which may be used as such or converted to other industrially important sulfur compounds, some of which are discussed later. 

Because it is cheap, calcium hydroxide is used in many chemical processes that require a strong base. It is used in the production of sodium hydroxide, ammonia, bleaching powder, and many other chemicals. Calcium hydroxide is also used as an insecticide in the form of lime-sulfur spray, in water softening, and in the production of numerous materials such as stucco and mortar which are widely used in the building construction industries. 

Uses Folpet is a foliage fungicide. It has several formulations, (e.g., Vinicoil, Captafol, Dinocap, and wettable powders and dusts). Folpet is no longer sold in the United States. Folpet is incompatible with strongly alkaline preparations such as lime sulfur.2,12,17,50... 

San Jose Scale Lime-sulfur Wash. State 08... 

In 1776 when the Nation was born, we had two useful fungicides for food crops, elemental sulfur and copper sulfate. During the century before the founding of ACS, we added only one more, lime-sulfur in 1803 and this was only a variant of elemental sulfur. Six years after ACS was founded, Bordeaux mixture was born of one of those accidents that Pasteur said happens to the prepared mind. 

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