UTIIJZATIOX OI' SIIIM.MI' WASTK 



119 



pi-('iVi';ibl(', since it acconiplislics iiai(;ili<»ii at the same time. Sti'ai<ilit 

 stcaniini!: <2,"ivos a {)r()(luct that has a h)\v(M' water content than thi; 

 f)rininal heads, but, in order to accomplish j)reservation, tlie stock 

 which has tlius been steamed at 10 pounds pressui-e for '1 lioui's will 

 recjuire the same amount of acid as the iri'i'cn stock. 



The waste is collected in heavy mesh baskets. These baskets 

 should have handles extendino- out from the sides to facilitate cai'- 

 rying and to act as supports in the cookiuf; vats. The total capacity 

 of the baskets should be 5 bushels, but they should be only half full 

 to permit suspended a^jitation. The half-filled baskets are carried 

 into the cookin<>; room, or covered space outside of the shrimp cook- 

 \w^ room, and lowered into the boilin*; water in the w^ooden vats. 

 The ([uantity of water in the vats must be sufficient to permit the 

 heads to move freely in the baskets. Ten minutes of active b()ilin<z 

 is sufficient for the i)reliminary preservation. The baskets are then 

 removed to the mixing platform, wdiere sulphuric acid is added at 

 the rate of 240 pounds per ton, or 12 pounds per basket. Mixing 

 is accomplished in the same manner as described for the non?(jnk 

 acidulation method. 



Chemical a/urli/sis. — The chemical analysis of three samples of 

 stock prepared by the cooking and acidulation methods described 

 above, varying the amount of the acid added, are given in the first 

 three columns of Table 5. When shrimp heads are treated with 

 acid without cooking, the results depend on the quantity of the acid, 

 which will vary with the degree of spoilage of the heads before the 

 treatment started. When such waste is immediately attended to, a 

 product can be obtained with an analysis approximating that of the 

 last column in Table 5. 



Table .j. 



-Chemical composition of fertilizer niuterials prepared hi/ the acidula- 

 tion of cooked and uncooked material 



Items 



Cook and acidulation method' 



Batch 1 Batch 2 Batch 3 



Noncook 

 and 



acidula- 

 tion 



method 



Yield 



Moisture 



Proteins (dry basis) 



Calcium phosphate (dry basis)-.. 



Potassium oxide (dry basis) 



Calcium suphate (dry basis) 



Sodium chloride (salt, dry basis). 

 Ether extract (dry basis) 



lod ine pa; ts per billion. 



Per cent 

 26.8 

 n.8 

 45.42 

 7.71 

 .75 

 7.66 

 2.5 

 3.0 



Per cent 

 31.4 

 11.3 

 43.19 

 7.64 

 .52 

 7.93 

 2.4 

 4.7 



Per cent 



35.9 



11.6 



41.28 



6.58 



.71 



12. 83 



2.9 



4.1 



Per cent 

 26.6 

 11.9 

 50.4 

 5.45 

 .46 

 5.31 

 4.0 

 3.0 



5,800 



7,300 



7,500 



6,100 



1 Varving quantities of acid were used for acidulating the cooked waste. 2 per cent, by weight, of acid 

 (based upon weight of stock) was used in acidulating batch 1, 3 per cent in batch 2, and 5 per cent in batch 3. 



To insure the proper flow of materials through the plant the 

 process will require the services of but 2 men working all the time, 

 or 3 men leisurely. The cooking operation can be started just after 

 the last of the shrimp has been placed on the tables. The three men 

 usually employed for this who are at present unemployed can 

 begin the processing, thereby extending their w^orking day. The 



