CA1165777A - Calcium ammonium lactate and process for preparing same - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A process for the preparation of calcium ammonium lactate in solid, crystalline form which comprises reacting lactic acid with ammonia in the presence of a calcium compound and isolating the desired product. The calcium compound may be a salt with a strong mineral acid. It may also be an alkaline salt, and used with a strong mineral acid The process produces the novel compound calcium ammonium lactate in pure form. The product is useful as a feed for ruminant animals which may also contain forage, roughage or other plant products which become incorporated in the solidified product.

Description

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The present invention relates to calcium ammonium lact-ate and a process for its preparation. This application is a divisional application o~ Patent Application No. 363,866 filed November 3, 1980. As described in that parent application calcium ammonium lactate is a constituent formed in the preparation of solidified forms of fermented ammoniated condensed whey. However, the compound is a useful nutrient on its own.

BACKGROUND OF THE INVE~TION

FACW is a liquid feed supplement which is manufactured by fermenting whey with lactic acid producing bacteria, such a Lactobacillus bulqaricus, ln the presence of ammonia. The fermentation of whey converts carbohydrate to lactic acid, which is neutralized by ammonia to form ammonium lactate. The fermentation also multiplies the bacteria, which consequently provide additional protein. The fermentation product, which typically will contain 6 to 16% solid matter, is then concentrated by evaporation typicaLly to a solids content of 40 to 6~%.
Since ruminant animals can utilize ammonium salts as a source of n~trogen or synthesis of protein, FACW i8 useful as a feed supplement for them. As a liquid, it can be applied to other ration components, such as shelled corn silage, oats, or oil seed meals. It would be useful, however, to have F~CW
available in a solid form, for example, for use on farms which are not equipped to use liquid feed ; supplements.

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Protein supplement and mineral blocks, pellets or other feeds processed via binding are normally made with expensive presses using binders such as molasses, lignin sulfonate or bentonite.
These methods often require steam conditioning of the meal prior to pressing and the application of high pressure (2000 to 3000 psi). The method of the parent application while compatible with this equipment, is a basic improvement in that this equipment is not necessary and little or no pressure or heat need be applied to form blocks. This invention offers considerable savings of time, ener~y and capital over current practices.
SUMMARY O:F THE INVENTION
In accordance with the invention of the aforementioned parent application FACW or other liquid substances containing similar concentrations of ammonium lactate and total solids can be solidified by mixing it with certain calcium salts. Depending on the salt used and the conditions of addition, substantial amounts of heat can be generated. At elevated temperatures the FACW or ammonium lactate-containing substance can be main-tained as a liquid. The rate of solidification in turn can be regulated by controllin9 the rate and extent of cooling. For example, with calcium chloride, the mixture typically begins to thicken at ~5 to 30C and can solidify completely within an hour, The solidified product reaches maximum hardness after one to several days. This hardening is not associated with evaporation of water, since it w$11 occur in an air-tight package.
The method is applicable to the manufacture of solid FACW in various forms. In its raw form, st7t~ ~

it can be solidified in molds to form lick blocks or cubes, or it can be extruded to produce pellets or granules. The solidified material can be crushed to form a powder or it can be "shaved" to produce flakes.
Trace ingredie~ts such as minerals, vitamins or drugs can also be added to the FACW prior to processing. Substantial amounts of molasses, corn steep liquid or other feed ingredient also may be added.
The aforesaid composi-tions may be used to make animal feed products in which they bind products such as grains, roughage and forage materials into blocks, cubes or pellets~ The compositions serve as excellent binding agents when blended in liquid form with those products and permitted to solidify. Typically such mixtures will contain 20 to 40% FACW and 1 to 3~ added calcium. Prior to solidification the mixtures can be poured and/or compressed into range blocks or cubes or extruded to form pellets. The compressed mass can then harden in twenty minutes or less. Unlike conventional binders these compositions are believed to serve to "cement" the solid product particles rather than serving as a simple "adhesive". For this reason the application of excessive pressure is not required to achieve solidification.
Thus the method of the parent application involves pro-ducing a ruminant animal feed which comprises solidified fermented ammoniated condensed whey which method comprises ,, , ~. :

~) 3a ~a) mixing fermented ammoniated condensed whey with an effective amount of a calcium salt of a strong mineral acid to cause the solidification of said fermented ammoniated condensed whey, and allowing the resulting mixture to stand until it has solidified; or (b) mixing fermented ammoniated condensed whey with a calcium compound which is reactive with a strong mineral acid to form a calcium salt of said strong mineral, adding a strong mineral acid to neutralize said compound, the amount of said calcium compound being effective to cause solidification of said fermented ammoniated condensed whey, and allowing the resulting mixture to stand until it has solidified.
This invention is concerned ~ith the novel compound calcium ammonium lactate. The method for producing the compound comprises reacting lactic acid with ammonia in the presence of a calcium compound.

MECHANISM OF SOLIDIFICATION
As previously described, FACW contains ammonium lactate as a primary constituent. It can exist as a solid, but since it is ~0 highly hydroscopic it remains li~uefied under normal atmospheric conditions. The mechanism by which FACW is solidified by the in-vention is not fully understood. However, it is believed to involve the formation of calcium ammonium lactate dihydrate (CAL), a solid crystalline substance. As presently understood, solvated calcium combines chemically with the ammonium lactate in FACW, resulting in the production of the CAL salt which crystallizes l~ 7 ~ ~ , and/or precipitates in mass to effect total solidification.
It has been found that in some cases, calcium ammonium lactate forms as a byproduct in the manufacture of FACW. The CAL
sometimes deposits in manufacturing equipment as a sediment, for example in pipes or storage vessels. This deposition can be pre~
vented by removing calcium from the whey used to make FACW. Such removal can be accomplished by ion exchange, prior to fermentation.
A suitable ion exchange system is the resin Amberlite* 200.
Conversely, CAL can be obtained by purification of FACW, i.e., by separating CAL crystals from FACW to obtain substantially pure CAL.
Calcium ammonium lactate salt (CAL) has been synthesized in the laboratory in the following manner: 500 parts by volume of the solution in lactic acid is neutralized with 257 parts of aqueous ammonia (27.7% NH3) and 5.55 parts by weight of Ca(OH)2 or (1.1 parts CaC12 2H20). The mixture i5 cooled to room temperature, pH adju8ted to 6.8 with 1.0 NaOH solution and diluted to 1 liter with water. After standing 4 to 7 days, well-formed crystals will form u~ually, however, seeding with CAL crystals and agitation may be necessary. The total crystal yield is approximately 5% by weight of the prepared solution.
The chemical composition of the resulting salt is as follows:

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s Constituent Percent Calcium B.6 Ammonia Nitrogen as N~4 7.7 Lactic Acid expressed as C3H503 74.4 Water 11.1 Total102.8 lAverage of 6 determinations.
The empirical formula of the compound based on the above analytical data is Ca~NH4)2 (C3H503)4 2H20, Unequivocal confirmation o~ ~his empirical formula has not been made.
The crystalline solid is characterized by monolithic symmetry. The compound does not have a distinct melting point, but appears to lose waters of lS hydration at 120C and decompose at l90iSC. CAL is very soluble in water, slightly soluble in aqueous ammonia and insoluble in ethanol. The solid has a specific gravity of 1.47.
Calclum ammonium lactate is useful in its own right ac a feed supplement for ruminant animals, CAL
contains approxi~ately 37.4 percent by mass of crude protein equivalent and the lactic acid constituent can serve a3 a valuable source of metabolizable energy.
Calcium is an essential mineral of ~reat nutritional importance. All of the constituents contained are valuable sources of animal nutrition making CAL a concentrated feed supplement that contains total ~eed value.
DETAILED DESCRIPTION
The invention of the parent application is appli-cable to FACW obtainable from various types of whey and having a variety of compositions. FACW contains, as speci-fied i5~7'~

in section ~573.450 of the Federal Register, 35 to 55%
ammonium lactate.
The calcium salts which are used in accordance with the invention are salts of strong mineral acids, such as calcium chloride, calcium sulfate and calcium phosphate. Calcium chloride is preferred, being effective in smaller quantities, and producing harder products, than calcium sulfate, which in turn is more effective than calcium phosphate.
Effectiveness is believed to be correlated with water solubility. It is possible also to use alkaline calcium salts such as calcium carbonate, calcium oxide or calcium hydroxide. However, when alkaline calcium salts are used, a mineral acid must be added in an amount sufficient to neutralize, so that the FACW is not rendered alkaline, so as to prevent loss of ammonia. Preferably sufficient mineral acid is added to form the calcium salt with all of the calcium.
The amount of calcium required to solidify an FACW-containing feed to any specified hardness generally has to be determined experimentally. It has been found that 6 to 10~ calcium, by weight of FACW, i8 generally sufficient. This amount is the percentage o calcium. The amount of any particular calc~um salt must be adjusted to give the appropriate amount o calcium.
The most elementary application of the method of the parent application is the solidification of FACW. The FACW and ¢alcium salt are mixed at room temperature to dissolve 0 the 8alt and the mixture poured into a suitable mold or hardening. It is best to slowly add this salt while vigorously mixing FACW to eliminate clumping and hasten its solution. If an alkaline calcium salt is used in combination with mineral acids, as described above, the acids are best added to the FACW during .... ,, .. .. ,, . _ .....

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agitation followed by the slow addition of the alkaline salt. If calcium chloride (CaC12 2H20) is used singly or if mineral acids are added prior to the addition of an alkaline salt, extensive heat is generated Calcium chloride has a positive heat of solution and typically produces a temperature ~ise of 1 to 1.5C (2 to 3F) for each percent of the dihydrate added. When mineral acids are used in combination with alkaline calcium salts, the heats generated result primarily from the solution of the acids. The neutral~zation of the acidified FACW by the alkaline salt is not significantly exothermic. A
rise o 1.5C (3F) is typically observed for each percent of mineral acid (95% H2SO4 or 85% H3PO4) added.
The FACW-calcium mixture can be maintained as a free flowing liquid if the temperature is maintained above the temperature at which solidiication is spontaneously initiated. This critical temperature is typically 25 to 30C but can vary depending on the exact composition o the FACW, the calcium salt used, the amount of calcium added and the rate of cooling.
If the FACW prior to calcium addition is at room temperature (20C), the elevated temperatures obtained following typical additions of calcium chloride or mineral acids plus alkaline salts is sufficiently high to maintain the FACW-calcium mixture in a liquid state. For example, if an FACW-calcium mixture is to contain 20% by mass o the d~hydrate, with a tempera-ture o 20C prior to blending, the temperature of themixture will be typically 40 to 50C following com-plete solution o the calcium salts. Such a mixture will remain as a liquid for a prolonged period, unless it is cooled. If the additions do not result in a mixture having a temperature that is greater than the 6'j~7'~

critical solidification temperature, sufficient heat must be applied to the FACW fraction before blending to prevent premature solidification.
By regulating the rate and extent of cooling, the rate of solidification can be controlled.
Relatively rapid solidification can result if the fluid is cooled at a specified rate to a temperature that nearly equals or is slightly lower (supercoolingJ
than the critical temperature before being poured into a mold, Once the critical temperature is attained, the product can be maintained as a liquid for a period of approximately 2 to 5 minutes, which is sufficient time to transfer the slightly thickened ~luid from the mixing vessel to the solidification mold. Once solidification is initiated, a hard, dry product can result in about 15 minutes or less. The exact rate and extent of cooling employed when applying this method must be determined experimentally and will vary with the formulation used and the FACW composition, It is necessary to control the rate of cooling so as to permit mold pouring at the critical temperature or during the supercooling phase. If cooling is too rapid, solidification can result prematurely and the method cannot be applied to attain the desired result, Rapid solidification is desired when insoluble materials such as minerals or grain fragments are slurried or suspended in liquid FACW
prior to initiating the solidification process, When the process is controlled to produce rapid solidifica-tion the suspended material can be homogeneously distributed in the finished solid. This process is especially applicable to the production of lick blocks containing insoluble matter where the matter must be homogeneously suspended.

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If the FACW mixture to be solidified contains no suspended solid matter, it may be desirable to implement a slow-setting procedure. This procedure is simpler to employ, since careful regulation of the cooling rate is not necessary. The FACW-calcium mixture is simply maintained at a temperature that is greater than the solidification temperature, poured into an appropriate mold and permitted to cool (usually under ambient conditions) until the solidification temperat~re is attained and solidification is achieved. With this method, solidification usually occurs in from 1 to 6 hours depending on the formulation used, the initial temperature of the fluid and the cooling conditions.
Generally the temperature at which the fluid is poured should be at least 2 to 5C above the known solidification temperature so as to avoid premature solidification that could occur if pouring were attempted at a slightly lower temperature. If the temperature is more than 5C above the known solldification temperature, solidiication will be delayed.
In addition to the production of solidified F~CW in molds, this method can be applied to the production of FACW pellets or cubes using commonly known extrusion type devices. To apply these device~
to liquid FACW-calcium mixtures at elevated tempera-tures, the mixtures must be cooled to the point at which solidification is initiated ~or supercooled) and forced through the extrusion device precisely when the desired consistency is attained. When using such a process, the rate and extent of cooling have to be carefully regulated so that the material is thickened to a desirable consistency just prior to being forced through the die of the extrusion device. After it has 7 f been formed, th~ extruded material can harden completely within minutes. The exact timing must be determined by trial for each formulation used.
FACW solidification can be conducted also with the in-clusion of other nutrients, such as molasses, corn steep liquid, yeast extract products, minerals and vitamins. In addition, drugs added to feed products may be included depending on the final use of the product. For example, Rumensin could be added to blocks, pellets or cubes for feeding cattle. In general, larger amounts of calcium salt are needed to attain a desired hardness when the FACW contains excessive amounts of molasses than when the process is practiced with FACW
itself. Mix~ures containing up to 25 parts by weight of molasses for each 100 parts of FACW may be solidified using conventional amounts of the calcium salts. Higher levels than 25 parts of molasses may be used, but the level of calcium may have to be elevated. Other ingredients may also influence solid-ification, and trial and error must be implemented to determine the level of calcium required to effect hardening.
A more sophisticated application of this method i~ the use of FACW-calcium mixtures to bind forage, roughage and other plant products when producing protein-concentrate pellets, cubes or range-blocks. It is best to premix the FACW and calcium salt maintaining the temperature high enough to prevent premature solidification, blend the resulting mixture with the ruminant animal feeds again maintainlng an elevated temperature, and compress the blend in a mold or apply extrusion-type processing.
In such products it is generally desirable to include about 30 to 40% by weight of the FACW-calcium salt ll mixture. The exact amounts of FACW and calcium required for solidification will vary with the nature of ~he ingredients included in the formulation, and the desired hardness of the block. The exact formulation must be determined experimentally for each intended binding application.
When feeds of this type are produced using FACW, the regulation of temperature during production is critical to the success of the process. Solidifi-cation of the FACW fraction must be prevented untilthe feed mixture is fully blended and compacted or extruded to its final shape by maintaining it above the solidification temperature. If solidification is premature, the ingredients will not bind adequately.
Generally if the li~uid FACW-calcium premix and the plant ingredients are blended rapidly and compressed or processed immediately, a well bound product will result, even without auxiliary heating.
Generally, when the liquid FACW-calcium mixture is at 40-50C, and it i8 blended in normal proportions with the plant product mixture at room temperature, the temperature of the resulting blend is low enough to initiate solidification of the FACW-calcium fraction, However, the mixture generally will remain suffici-ently moist and sticky to permit good compaction tooccur or a period of approximately 5 to 10 minutes.
If the blended feed is to remain for an extended period of time before compression processing, the total feed must be heated so as to maintain it above the solid~ication temperature.
After blending the FACW, calcium salt and plant ingredients, the mixture is compressed in the desired form and left to harden by the solidification of the FACW. During ~ormation sufficient pressing must be applied to compact the product to a convenient . ~

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density, i.e., remove extraneous pockets of air. If the solidified product is not to cure or be stored in a mold, sufficient pressure must be applied to maintain the shape of the product until solidification is sufficiently complete to allow the shape to be maintained before the product is removed from the mold.
The following examples illustrate the method wherein calcium ammonium lactate was used in the preparation of solid whey.
All parts and percentages are given on a weight basis, unless stated otherwise.
EXAMPLE _ The following formulation was used to produce a 30-pound lick-type range block:
Inqredient Percent FACW (60% solids) 80 CaC12 2H20 20 A 5-gallon bucket was used as a mixing vessel, with agitation from an air-driven barrel mixer fitted with a single set of three 2-inch blades. The mixlng vessel was placed within a 15-gallon tub which was filled with water for rapid cooling of the blended feed ingredients. The mold used to shape the lick block was a 3-gallon plastic tub (6 x 11 x 14 inches). Utilization of the plastic tub permitted easy removal of the finished block, since the inside walls were smooth and slightly tapered at the open end.
The CaC12 2H20 fraction (6 pounds) was poured slowly into the vigorously mixing FACW fraction ~24 pounds), The mixture was agitated for approxi-mately 5 minutes to assure complete solution of the added salt. After mixing, the temperature of the FACW
mixture was elevated 33C from room temperature to approximately 56C. After the initial 5 minutes of mixing, cold tap water was circulated through the cooling vessel and the fluid cooled at an approximate rate of 1.5 i 0.5C per minute. The fluid mixture began to thicken when a temperature of approximately 31C was reached, and it was immediately poured into the mold for solidification. The mixture hardened in about 10 minutes and was removed from the mold after 1 hour. The block attained maximum hardness after two or three days of curing.
The finished block was chemically analyzed and observed to contain the following:
Constituent Percent ~/M) CPE 36.3 CPE from non-protein nitroaen 31.6 Lactic acid 29.8 Estimated solids 68.0 Calcium 5.85 This block was fed free-choice to a herd of heifers and dry cows under normal field conditions and was observed to provide adequate palatability and weatherability.

EXAMPLE II
A 30-pound lick-type block similar to that of Example I was prepared with the inclusion of black strap molasses from the following formulation:
Ingredient Percent FACW (60~ solids) 70 CaC12 2H2O 20 Molasses, Black Strap ~ 10 The procedure used to produce this block was similar to that employed in Example I. The FACW and r--~7r~r~J

molasses were premixed, then the calcium salt was added as previously described. This material required approximately six hours to solidify and several days to attain maximum hardness.
The finished block was chemically analyzed and observed to contain the following:
Constituent Percent CPE
CPE from non-protein nitrogen 28.4 Lactic acid 27.9 Estimated solids 69.5 Calcium S.78 This block when used in the field as a lick-feed was palatable and weathered well.

EXAMPLE III
The following formulation was used to produce a 30-pound FACW range block using calcium carbonate plus acids for solidification:
In~redients Percent FACW (60% solids) 68 CaCO3 15 85% H3PO4 15 95% H2S~4 2 In addition to neutralizing the alkaline effect of the carbonate, the acids served as a valuable source of phosphorus and sulfur.
This block was prepared using the apparatus described in Example I. The acids were first added to the FACW and mixed. Following the addition of the acid, the temperature of the mixture rose from 23C to 48C. The CaCO3 was next added slowly to the warm FACW-acid mixture over a period of about 15 to 20 minutes. Extensive foaming, resulting from the production of carbon dioxide, was observed during and 7'~

following the addition of CaCo3. Slow addition was used to control the neutralization reaction and prevent excessive foaming. After carbonate addition was completed, the blend ~ontinued to produce gas slowly for periods exceeding one hour.
After one hour, cooling was initiated. The liquid began to thicken when a temperature ~f about 27C was attained, and it was immediately poured into the mold.
Carbon dioxide production continued after the thickened liquid was transferred to the molds, and the solidifying product expanded as the evolved gases were entrapped. The volume of the dried block was about 50~ larger than the freshly poured product. The product solidified in about six hours and attained maximum hardness afte~ several days of curing.
The finished block was chemically analyzed and found to contain the following:
Constituent Percent CPE 31.9 CPB from non-protein nitrogen 27.5 Lactic acid 26.2 Estimated solids 70.5 p~ 5.70 Calcium 6.42 Phosphorus 4.85 Sulfur 0.52 EXAMPLE IV
A 30-pound range block similar to that described in Example III was produced, with the inclusion of low moisture shelled corn, using the following formula:

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Ingredient Percent FACW (60% solids) 52.2 CaCO3 12.0 85~ H3PO~ 12.0 95% H2SO4 1.6 Ground corn, LMS 20.0 The procedure implemented was similar to that described in Example III. The corn fraction was added to the other premixed ingredients just prior to initiating the cooling operation. A temperature rise of 22C was observed during preparation of the premix. Solidification was initiated after cooling to approximately 32C. The thickening product was not poured until it had attained a consistency that would permit suspension of the corn fragments. The solidification was completed after about 6 hours and maximum hardness was attained after several days of curing. The block matter was physically similar to that produced in Example III, and the corn particles appeared to be uniformly distributed within the product, The finished product was observed to contain the following:
Constituent Percent CPE 28.5 CPE from non-protein nitrogen 22.6 Lactic acid 22.3 Estimated solids 74.0 pH 5.51 Calcium 4.50 Phosphorus 4.43 Sulfur 0.26 ~ ~ ~; 5 7 ~ ~

EXAMPLE V
A 200-gram high soy range cube was produced with FACW plus calcium serving as the binding agent using the following formulation:
Ingredient Percent Soybean meal 65.7 FACW (60% solids) 28.1 CaC12 2H2O 6.2 The FACW and CaC12 ingredients were premixed with vigorous mechanical agitation for about 5 minutes. This premix was then blended with the soybean meal in a 500-liter stainless steel beaker using a large metal spatula. Blending was conducted for 3 to 5 minutes (just long enough to attain mixture uniformity) and immediately transferred to a 400-ml plastic beaker which served as a solidification mold. The blend was tightly packed by hand pressure, covered with plastic film and permitted to remain undisturbed for several hours before removing the mold. The mixing and packing operation employed in this example was sufficiently rapid to avoid premature solidification. The product was sufficiently moist and sticky at the time of packing to attain good 5 binding.
The finished product was dry, observed to be of a desired hardness, and displayed good weathering characteristics. The finished product was estimated to contain the following:
Const_tuent Percent CPE 42.5 CPE from non-protein nitrogen 9,9 Lactic acid 10.1 Estimated solids 80.1 Calcium 1.90 tj~t~7 EXAMPLE VI
A 200-gram soy range cube similar to that described in Example V was prepared with the inclusion of black strap molasses, usinq the following formula:
Ingredient Percent Soybean Meal 59.1 FACW (60% solids) 25,3 Molasses, Black Strap 10.0 CaC12 2H2O _ 5.6 The preparation of this cube was similar to that produced in Example V. The molasses was premixed with the FACW prior to the addition of the calcium salts. This product was also dry, observed to display desired hardness and had good weathering characteristics. The finished product was to contain the following:
Constituent Percent CPE 3B.5 CPE from non-protein nitrogen 8.91 Lactic acid 9.11 Estimated solids 81~8 Calcium 1.80 EXAMPLE VII
Range blocks similar in composition to commercially produced protein blocks were produced using F~CW and CaC12 as binding agents in the following three formulations;

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Percent IN~REDIENTS B~XX 1 B~X~ 2 B~X~ 3 Soybean o~ meal 47.9 40.4 39.3 FACW 26.7 32.8 ~.1 Dehydrated alfalfa 9.209.20 9.20 Linseed meal 1.83 1.83 1.83 Calcium ~oride, dihydrate 5.857.20 9.00 Amm~nium p~yphosphate 3.113.11 3.11 Amnonium sulfate 0.5480.548 0.548 Sodium chloride 4.57 4-57 4-~7 Zin~ sulfate, heptahydrate 0.124 0.124 0.124 M~anese sulfate, m~nohydrate .0496 .0496 .0496 Ferric sulfate .0578 .0578 .0578 ~agnesium sulfate, dihydrate 0.122 0.122 0.122 15 Cupric s~fate .0952.09S2 ,0952 Cobalt sulfate .00194.00194 .00194 Scdium iodide .00066.00066 ,00066 Vitam~ns ~ #
~arAI, 100 100 400 20 #50,000 and 12,500 U.S.P. units of Vitamin A and Vitamin D3, respectively, added per pound of block.
The FACW and CaC12 components were premixed and added collectively to the remaining dry ingredients, which were also premixed. The FACW-CaC12 25 premixes were prepared in a 2-gallon plastic bucket.
Each FACW fraction was blended vigorously with a Grohav air mixer fitted with a single set of 2-inch blades during the slow addition of each respective CaC12 fraction. Rapid mix~ng and slow addition was 30 used to prevent agglomeration and clumping of the CaC12. Each FACW-calcium premix was mixed for about five minutes after the addition to assure that CaC12 had been totally dissolved. The temperature of each FACW fraction was elevated during the premixing i5'~

operations in which CaC12 was added. The temperature of the premixes were elevated about 20C with the 22%
additions of CaC12 2H20.
The premixing of the dry ingredients was conducted in a Davis batch horizontal ribbon-type mixer (Model ~S-l) with a mixing capacity of five cubic feet. The liquid premix was poured slowly and uniformly onto the mixing dry ingredients to help assure uniformity of mix. After the liquid addition was completed, the mixing was continued for an additional five minutes. Any feed that was sticking in excess to the ribbon blades or remaining stagnant in the lower corners of the mixer was then removed with a metal spatula and mixing was continued for an add$tional five minutes.
Each of the blendings of feed ingredients mixed loosely and freely in the horizontal ribbon mixer. The mixtures prepared to produce blocks 1 and

2 (27 and 33% FACW, respectively) were moist and slightly sticky. The block 3 mixture (41% FACW) was noticeably more moist and sticky. Before solidifica-tion, the block 3 mixture was wet and almost paste-like. Even though the three mixtures blended uniformly without clumping, they were observed to pack tightly if compressed in one's hand.
Excessive mixing times had to be avoided, since solidification of the feed mixes initiated in about 15 minutes or less. If not removed from the mixer expeditiously, the mixtures were observed to form a hard, relatively dry crust on the back side of the ribbon blades and on the mixer walls in areas of stagnant mixing. Also, if mixed excessively, the feed mixtures were observed to dry to an extent that did not permit adequate packing, i.e., the feed particles lost their adhesive nature.

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The moist, freshly-prepared feed ~lend~ were easily packed with good uniformity into the block mold. Some disuniformity was observed in the density of the pack due to the layered addition of the feed mixture, i.e., the top portion of each strata was observed to be slightly more dense than the bottom portion. The moist feed materials prepared ~o produce blocks 1 and 2 compressed to very firm solid masses that were not easily crumbled. The block 3 mix~ure remained somewhat soft and pasty immedi~tely after packing.
The feed mixtures were removed immediately from the mixer and packed into a block solidification mold. The mold was a rectangular wooden box, constructed to approximate the shape and size of most commercial range blocks. The faces of the mold were held together by screws so as to permit the disas-semblement of the box for easy removal of the finished block. The open end from which the mold was filled was filled with a movable lid that fit within the box. After f~lling, a 25-pound weight was placed on the movable lid so as to apply a constant pressure to the solidifying feed mixture.
Each feed mixture was packed manually in the golidification mold with the butt end of a 4-foot length of 4 x 4" board weighing approximately ten pounds. The wet feed was added to the box in fractions weighing 1-2 pounds each with each fraction being thoroughly tamped ~packed) before the addition of each subæequent fraction. Once the mold was filled, the lid was placed on the exposed feed surface and weighed.
Even though the feed blends were left in the mold ~or 4 to 6 hours, it appears that blocks 1 and 2 would retain their shape and remain firm if the mold was removed immediately after packing. The blocks would likely maintain some surface stickiness but would probably be resistan~ to crumbling and breakage. After being compressed into the form of a block, they could be immediately packaged and stacked without being damaged.
~ he mold was removed from block 1 with little difficulty. The mold was easily freed from the block mass with little resistance and little feed remained adhered to the wood. The block surface was dry and 10 firm. The mold, however, was not easily removed from blocks 2 and 3. Considerable force was needed to pull away from the wooden mold from block 2. Large fragments of the hardened feed adhered to the wood and were torn from the block. The block surface was still 15 sticky but remained firm. This problem possibly could have been alleviated if the mold were lined with sheet plastic or other non-stick surface prior to filling.
Block 3 adhered even more firmly to the wood mold. A
metal spatula had to be forced between the block and the mold to release it. The block surface remained very sticky and although it was firm, an impression could be made in it with the force of a person's thumb, After being bagged and allowed to stand for a 25 one-week curing period, all of the blocks were very hard and dry and displayed no surface stickiness The blocks as a whole were not easily crumbled, but some crumbling was observed at the edges of the block surfaces.
Chemical analysis of the blocks provided the following information:

~i! ;. i~f~iS7 NUTRIENT Block 1 Block 2 Block 3 Crude protein equivalent 39.5 38.1 36.3 CPE derived from NPN 12.4 15.4 17.7 ~ Lactic acid 10.5 12.8 17.6 5 % Drymatter 83.8 81.7 78.3 p~ 5.68 5.64 5.57 % Ash 12.1 12.8 15.4 % Calcium 1. 64 2.13 2.37 % Phosphorus O . 91 0 . 69 0 . 71 10 % Sulfur 0-07 0.10 0.18 ~ Sodium 1.58 1.41 1~98 % Chlor ide 7 . 8 10 11 The blocks were fed and consumed by cattle in approximately the correct amount for their size and 15 basal ration. These blocks weathered well and were judged to be equivalent to normal feed blocks.
This process is not restricted to these examples or devices but could be carried out using commercially available food and feed industry 20 equipment by control of temperatures, FACW level and calcium level. ~he molds used could be any commercially available contai~er provlded it was sufficiently rigid. Pressing of the materlal into the mold could be by any device such as cheese block 25 presses or other such commonly used device. Feed block presses could also be used but high pressure is not required.

Claims (12)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for the preparation of solid, crystalline calcium ammonium lactate which comprises reacting lactic acid with ammonia in the presence of a calcium compound and isolating the desired product.

2. A process as claimed in claim 1 wherein the calcium compound is a calcium salt of a strong mineral acid.

3. A process as claimed in claim 2 wherein the salt is selected from calcium chloride, calcium sulfate and calcium phos-phate.

4. A process as claimed in claim 1 wherein the compound is an alkaline calcium salt and a mineral acid is added in an amount sufficient to neutralize the mixture so as to prevent loss of ammonia.

5. A process as claimed in claim 4 wherein the salt is selected from calcium carbonate, calcium oxide or calcium hydroxide.

6. A process as claimed in claim 1 wherein lactic acid is neutralized with aqueous ammonia and either calcium hydroxide or calcium chloride dihydrate is added thereafter and isolating the desired product.

7. Calcium ammonium lactate in solid, crystalline form whenever prepared by the process of claim 1 or an abvious chemical equivalent thereof.

8. Calcium ammonium lactate in solid, crystalline form whenever prepared by the process of claim 2 or an obvious chemical equivalent thereof.

9. Calcium ammonium lactate in solid, crystalline form whenever prepared by the process of claim 3 or an obvious chemical equivalent thereof.

10. Calcium ammonium lactate in solid, crystalline form whenever prepared by the process of claim 4 or an obvious chemical equivalent thereof.

11. Calcium ammonium lactate in solid, crystalline form whenever prepared by the process of claim 5 or an obvious chemical equivalent thereof.

12. Calcium ammonium lactate in solid, crystalline form whenever prepared by the process of claim 6 or an obvious chemical equivalent thereof.