ANSI T 650 OM-2005 Solids content of black liquor.pdf

1、TAPPI/ANSI T 650 om-15 SUGGESTED METHOD 1971 REVISED 1979 PROVISIONAL METHOD 1984 OFFICIAL TEST METHOD 1989 REVISED 1999 REVISED 2005 REVISED 2005 REAFFIRMED 2015 2015 TAPPI The information and data contained in this document were prepared by a technical committee of the Association. The committee a

2、nd the Association assume no liability or responsibility in connection with the use of such information or data, including but not limited to any liability under patent, copyright, or trade secret laws. The user is responsible for determining that this document is the most recent edition published.

3、Approved by the Standard Specific Interest Group for this Test Method TAPPI CAUTION: This Test Method may include safety precautions which are believed to be appropriate at the time of publication of the method. The intent of these is to alert the user of the method to safety issues related to such

4、use. The user is responsible for determining that the safety precautions are complete and are appropriate to their use of the method, and for ensuring that suitable safety practices have not changed since publication of the method. This method may require the use, disposal, or both, of chemicals whi

5、ch may present serious health hazards to humans. Procedures for the handling of such substances are set forth on Material Safety Data Sheets which must be developed by all manufacturers and importers of potentially hazardous chemicals and maintained by all distributors of potentially hazardous chemi

6、cals. Prior to the use of this method, the user must determine whether any of the chemicals to be used or disposed of are potentially hazardous and, if so, must follow strictly the procedures specified by both the manufacturer, as well as local, state, and federal authorities for safe use and dispos

7、al of these chemicals. Solids content of black liquor 1. Scope1.1 This method is designed to measure gravimetrically the solids content of weak and strong black liquors as they exist, or will exist, at the point of injection into the recovery furnace (1-3). 1.2 This method can be used to calibrate r

8、apid or routine control procedures. 1.3 The method will measure the “solids” remaining after removal of water and other nonaqueous volatile materials normally lost in commercial evaporation systems. 1.4 The sampling procedure is compatible with additional black liquor analytical procedures such as c

9、hemical analyses, heating value, etc. 2. Summary 2.1 Black liquor specimens are dried at 105C for a minimum of 6 h with inert surface extender and a controlled flow of dried air to increase drying rate and eliminate moisture entrapment. Strong black liquors are diluted to allow volumetric handling a

10、nd to reduce scum formation. 3. Significance This method will measure correctly the gravimetric “solids” of weak and strong black liquors to be used as fuel in recovery furnaces. The “solids” are what remains after the normal evaporation process. This method is the reference method and can be used t

11、o calibrate rapid procedures or sensors. T 650 om-15 Solids content of black liquor / 2 4. Apparatus and materials 4.1 Glass weighing bottle, low-form, ground-glass stoppered, about 70 mm internal diameter 33 mm high with an approximate capacity of 82 mL. 4.2 Oven, forced air, controlled at 105 3C a

12、nd adjusted so that the air will be replaced about once or twice per minute. 4.3 Sand, high silica ( 98% +) approximately 2030 mesh, that has been previously heated at 850C. NOTE 1: Diatomaceous earth and alundum have been found to react with residual carbonate and caustic in black liquors leading t

13、o significantly lower solids results. High silica sand is the only material found to be inert (4). 4.4 Plastic ware, volumetric flask, 500 mL bottle with cap; pipet or liquid dropper. 4.5 Balance, capable of weighing to 0.001 g or better. 5. Sampling and test specimens 5.1 Weak liquor will usually c

14、ontain fibers. Eliminate these by filtering through coarse filter paper or by inserting the pipet below the fibers, which tend to float to the surface. 5.2 Concentrated liquors should be diluted with distilled water to 20-30% concentration so that they can be handled as a fluid, be made homogenous,

15、and provide no chance of flashing when drying. This should be done by estimating the concentration of the sample and calculating the amount of liquor and water needed to give 20-30% concentration. A 500-mL volume of diluted sample is desirable if subsequent chemical analyses are required. 5.3 Proced

16、ure for diluting a hot liquor: Weigh an empty 500-mL or 1-L plastic bottle with cap to the nearest 0.001 g. Add an appropriate amount of distilled water and reweigh. Add the hot liquid black liquor to the bottle and cap immediately. Gently swirl the bottle to mix. When well-mixed, cool and weigh. Ca

17、lculate the dilution ratio. 5.4 Procedure for diluting a cold liquor: Liquor to be sampled must be in the liquid state to ensure homogeneity. Place the container with the concentrated sample in a hot water bath to melt it. Stir until the sample is liquid and homogenous. Sample and dilute as in 5.3 a

18、bove. 6. Procedure 6.1 Place 45 to 50 g of sand in the weighing bottle and heat the bottle and stopper in the oven (stopper off) at 105C to constant weight. Cool in a desiccator and weigh to the nearest 0.001 g. By means of a pipet or dropper, transfer enough specimen to the weighing bottle to ensur

19、e 1 to 3 g of dry solids. (For weak liquors under 30%, a 5- to 10-g specimen is required. For concentrated liquors, dilute as directed in 5.2 - 5.4.) Cap the bottle and weigh to the nearest 0.001 g . 6.2 Place the weighing bottle and stopper in the oven (stopper off) and heat for a minimum of 6 h. R

20、emove, cool in desiccator, and weigh (stopper on). Repeat this heating procedure at 1-h intervals until the weight loss is less than 0.1% per hour (approximately 0.001 to 0.003 g loss per hour). If samples are left overnight in the oven, the time to constant weight will be minimized. 6.3 Make tripli

21、cate determinations, weighing and diluting in separate containers (5.3). 7. Calculation All weights are in grams. 7.1 Undiluted liquors 100% specimensofWeightsolidsdriedofWeightSolids 3 / Solids content of black liquor T 650 om-15 7.2 Diluted liquors weightsampleOriginalweightSampleOHofWeightweights

22、ampleOriginalsampledilutedofWeightratioDilution2100)(% specimenofWeightsolidsdriedofWeightliquordilutedSolids % Solids (original sample) = % solids of diluted liquor dilution ratio 8. Report Report the average percentage of solids, based on the original weight of the sample, to the nearest 0.1%. 9.

23、Precision The following estimates of repeatability and reproducibility are based on data from an interlaboratory trial involving 5 laboratories and one sample of heavy black liquor. The trial was conducted in February 1998 using the T 650 om-89 revision of this method. Testing is based on 3 determin

24、ations per test result and one result per lab, per material. % Solids Material description Grand mean Range Repeatability r and r% Reproducibility R and %R Labs included Heavy Black Liquor 49.11 48.39 - 49.37 0.53 1.1% 1.22 2.5% 4/5 All data in % solids Repeatability and reproducibility are estimate

25、s of the maximum difference (at 95%) which should be expected when comparing test results for materials similar to those described above under similar test conditions. These estimates may not be valid for different materials or testing conditions. 9.2 The above are in accordance with the definitions

26、 of these terms in TAPPI T 1200 “Interlaboratory Evaluation of Test Methods to Determine TAPPI Repeatability and Reproducibility.” 10. Keywords Solids content, Black liquors 11. Additional information 11.1 Effective date of issue: April 21, 2015. 11.2 This method was originally part of T 625 “Analys

27、is of Soda and Sulfate Black Liquor.” 11.3 The 1979 version of this method (T 650 pm-79), which specified use of diatomaceous earth as the extender, is in error and should not be used. 11.4 In 1999 a Significance section was added and a new Precision statement was done. 11.5 Changes in the 2015 vers

28、ion include adjusting the mesh size of the sand in 4.3 and adjusting the amounts to be used in 6.1. The original sand was no longer commercially available. The following study was run at one lab doing duplicate measurements on three liquor samples to determine the effect of the sand mesh size. T 650

29、 om-15 Solids content of black liquor / 4 20-30 mesh sand 60-100 mesh sand Sample % solids % solids 1 12.51 12.55 2 18.29 18.25 3 21.72 21.59 References 1. Parker, J. L., Hensel, R. P., and Wagoner, C. L., “Measurement of Total Solids in Kraft Black Liquors,” Tappi 53 (5): 874 (1970). 2. Phillips, J

30、. H., “Determination of Total Nonaqueous Constituents in Pulp Mill Liquors,” Tappi 34 (10): 101A (1951). 3. Phillips, J. H., and Rubright, M. M., “The Determination of Total Nonaqueous Constituents in Pulp Mill Liquors, Part II, Application to All Types of Residual Pulping Liquors,” Tappi 36 (9): 392 (1953). 4. McDonald, K. L., Tappi 62(1): 80 (1979). Also private communication: Grace, T. G.; Nelson, W.; and Tostevin, J. E. Your comments and suggestions on this procedure are earnestly requested and should be sent to the TAPPI Standards Department.